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SONY CPD-G400 Chassis F99 CRT Monitor

1. Pin Name Dir Description 1 RED _ Red Video 75 ohm 0 7V 2 GREEN _ Green Video 75 ohm 0 7V 3 BLUE Blue Video 75 ohm 0 7 V p p 4 RES Reserved 5 GND Ground 6 RGND Red Ground 7 Green Ground 8 BGND Blue Ground 9 5 _ 45V DC 10 SGND a Sync Ground 11 IDO lt Monitor ID Bit 0 optional 12 SDA gt DDC Serial Data Line 13 HSYNC or CSYNC Horizontal Sync or Composite Sync 14 VSYNC Vertical Sync 15 SCL DDC Data Clock Line Note Direction is Computer relative Monitor Plug amp Play Communications in Sony model CPD G400 2 way DDC2B s SDA w clk CPU TC1001 SDA Serial Data 1 way DDC1 SDA is triggered by V sync What is Plug and Play Currently there are several levels of Plug and Play compliance DDC1 Display Data Channel 1 capable monitors can communicate with the display adapter in only one direction through an unused line on the stan dard VGA cable The DDC1 type of communication is the type of data channel from the display to the host continuously transmitting Extended Display Identification EDID information The video adapter is told what monitor is connected and its maximum resolutions and refresh rates DDC2B goes one step further by offering bi directional
2. CH1 140 v 1 1 1 88 This signal is amplified 0605 and applied to the primary winding of transformer at T602 pin 5 The SRT transformer has three groups of secondary windings e Pins 10 15 supply power to the monitor e Pins 16 18 supply voltage to the Horizontal centering circuit e Pins 2 3 return a sample of the transformer voltage to 1 603 The secondary voltage from T602 pins 2 and 3 are separated into two paths before fed back to IC603 pins 13 and 7 for control IC603 pin 13 The R635 path is used to monitor changes to the sec ondary load for mode changes between Normal Light and Active off operation IC603 pin 7 The path through D613 R642 D633 and R643 is used to coarse regulate the output voltage 1 603 uses this information to change the oscillator pulse width duty cycle for output voltage con trol A second regulation path into 603 9 is used for fine voltage correction R627 R693 4 7M 4 7M VIN 4 OOB 5 6V IC603 dos SW REG CONT TEA1504 SENSE 9 V CONTROL 6 VAUX at R643 613522 OHMS 47 R644 100 REGULATOR CIRCUIT R615 33 OHMS SWITCHING OSCILLATOR 22 pets HG 80V 5V HEATER TO CPU CPU IC1001 8 04 1198 1 28 00 Active off Mode The monitor can also operat
3. 1 1001 CPU ABL PROTECT 55 D BD 300V 1 901 Q901 FOCUS HV 115 DATA SYNCO ABL PROTECT ames H OUT PROTECT VD Y V SAW IN PROTECT PIN Q506 Q508 H SHAPE SYNC DEFLECTION BLOCK 18MONO4 1222 1 18 00 50 Horiz Vert Oscillator Oscillator Activity CPU 1 1001 houses the horizontal and vertical oscillator The internal oscillators operate as long as there is standby 5V supplied to the CPU even during the low power Active Off Burst Mode When sync is input the oscillator frequency will match the input sync frequency if it is within operating range Oscillator Frequency Mode Horiz Freq Location Vert Freq Location Sync range 30 107kHz 09 7 48 120Hz CN309 pin 5 No Sync 70kHz 1001 80Hz 1001 4 27 5Vp p 26 Oscillator waveform No input sync Horizontal Horizontal Oscillator Oscillator 70kHz 2usec TOkHz _ gt 12 5usec 12usec 51 Main H and V Sync Path Horizontal and vertical sync entering the monitor are selected by switch 1 009 and buffered by 1 006 These signals pass from the input A board to the CPU at the front of the D deflection board under the picture tube bell The sync levels are all at 5Vp p negative polarity up to CPU IC1001 Main Sync
4. One Oscillator Burst Name Location Voltage Channel1 Amplified Osc Q605 D 180Vp p Channel2 Oscillator Output IC603 pin 4 11Vp p Time base 200usec div 8 In this Active Off Burst Mode the voltage to standby regulator IC609 must still be regulated or it will become excessive about 40V Q609 performs the regulation for the standby 5V Because the D616 SCR is still turned ON the input voltage from D621 is increasing but in bursts When the input voltage at D621 C reaches about 15 6V ze ner D630 conducts turning on Q609 Q609 turns on 1 607 which outputs an oscillator correction voltage directly proportional to the input voltage from D621 C The correction voltage corrects the pulse width of the burst signal to keep the aver age voltage at D621 C at about 12V in the Active Off Burst Mode Measured Voltages Measured Voltages Location Normal Mode Active Off Mode IC607 pin 1 Supply voltage 13 3 13 4V input IC607 pin 2 Input 12 5 12 7V IC607 pin 5 Output 0 18 0 21V hot ground 607 6 Supply voltage 12 5V 9 3 9 5V hot ground output Q609 Base Input OV 0 1 Q609 Collector Output 6 9V 12 5 12 7V IC608 pin 1 Input 2 48V 0 2 IC608 pin 3 Output 5 39V 12 5 12 7V D616 Anode 200 B 199 4V 15 9 16V D616 Gate Burst Mode 8 86V 13 2 13 4 trigger D616 Cathode Regulator input 9 53V 13 4 13 5V 603 0605 SWITCH
5. 1 L V REGULATOR CIRCUIT 6 04 1202 1 24 00 36 Video Block The Video Processing Block contains several stages e RGB signal processing from the computer to the CRT cathodes OSD for Menu features CRT Bias RGB Signal Process Two computers can be connected to the CPD G400 monitor A front panel switch selects the input used The switch signal is applied to 1 008 which selects the RGB signal The input switch is also connected to 1 009 to simultaneously select the sync The selected horizontal and vertical sync signals are used to lock the oscillator inside CPU 1 001 The RGB signal is amplified by RGB Pre amplifier 1 001 and will output this IC unless the alternate OSD signal containing menu information is switched in The Input OSD switch is controlled by 003 signal 002 amplifies the input or and OSD input to a high level to drive the CRT cathodes OSD The OSD 1 003 makes the menu characters white screen for the Aging Mode and the Image Restoration feature and translates the analog cath ode current levels Ik into digital data for CPU IC1001 1 needs serial data clock and the H amp V oscillator inputs to support the RGB and BIk outputs These two outputs are used to make a menu display or white screen The Ik input is used when the image restoration feature is activated from the menu The Ik voltages are then sent out as data to the CPU for computation CRT B
6. gt BUFF Q507 E VIDEO OUTPUT 8 04 1210 1 19 00 46 G2 Control CRT Brightness The CRT brightness is determined by High Voltage Cathode Voltage e G2 Voltage The High Voltage is fixed and regulated by the HV regulating stage The cathode voltage carries the RGB picture signal from the computer This RGB signal arriving at the cathode varies from 20V bright to 200V dark cutoff The G2 voltage is used to set the maximum brightness of the picture This brightness white level is measured in degrees Kelvin and adjusted using the CATS software G2 Circuit 1005 1 1001 The voltage at the G2 CRT grid is set with data stored in ROM 1 1005 When the monitor is turned ON CPU 1 1001 using the IIC 12 bus retrieves this information along with other data When CPU 1 1001 communicates with RGB Preamp 1 001 the data pertaining to this IC is transmitted using the same IIC data and clock lines IC001 1 005 Some of this transmitted data sets the G2 voltage 001 uses this data to make an analog voltage that outputs pin 29 This is applied to inverter Op Amp 005 5 The output at pin 7 is applied to buffer Q001 emit ter The conduction of buffer Q001 reduces the voltage at the CRT G2 pin reducing overall picture brightness Start Up Brightness Reduction The G2 voltage is reduced slightly at power ON to provide a gradual pic ture brightness increase as the monitor warms up When the m
7. D921 5 6V 01003 5 6V R417 VFBP 3 3V 0405 your IC401 7 SELF DIAGNOSTIC BLOCK 12 1 609 5V 605 4 5 5V HEATER VOLTAGE REMOTE ON OFF RGB 001 OUTPUT RGB PRE AMP 1 002 0912 901 11 3 16V FBT T901 8 0911 R660 R656 200V R661 4MONOA 1203 1 19 00 Power Supply Block The power supply develops various voltages required by the monitor The CPU works with the switching power supply to enter a very low energy star compliant power saving mode when the external computer is turned Off but the monitor switch is still ON The CPU also activates this same power saving mode when a circuit failure occurs The monitor has sev eral major power supply sections Power Supply Sections Sections Function Degaussing Circuit Demagnetizes the picture tube at power ON Prevents a momentary short circuit to the Surge Protection Circuit Q607 AC line at power ON Reduces voltage fluctuations at power ON Switching Power Supply Develops multiple voltages needed by he IC603 Q605 T602 monitor Centers the picture by adding a DC voltage onto the H yoke winding H Centering Control 502 0519 Shunt 8 Stby Requlation IC608 Q609 Sets the switching power supply pulse width to maintain a stable power supply output voltage CPU Control IC1001 Switches the power supply into one of four
8. High Voltage Overview The purpose of this stage is to use the horizontal drive signal to manufac ture high voltage High voltage is used in various areas High Voltage Usage Voltage Purpose Where 27kV screen CRT anode accelerating Focus about 4kV CRT Focus CRT socket 1kV 300V CRT G2 accelerating Vertical dynamic focus output circuit CRT socket D board Q706 D board This stage consists of a HV manufacturing part and a regulating part The regulating part keeps the HV constant when there are changes in bright ness HV Manufacture HV Control IC901 makes two signals from the horizontal drive signal input pin 14 Fixed drive signal from IC901 pin 5 PWM signal from IC901 pin 3 Fixed Drive Signal 1 901 takes the horizontal drive signal that is input pin 14 and makes a positive going signal 9 6usec in the aging mode The width is a function of the input horizontal frequency This positive going signal outputs IC901 pin 5 and is used to turn ON and OFF drive HV Output MOSFET Q902 MOSFETs are often used in monitors because they have an even gain for a large frequency range Q902 amplifies the drive signal and the signal from the Drain is applied to the flyback s primary winding The flyback s secondary windings produce the various high voltages needed by the monitor 57 PWM Signal The PWM signal from IC901 pin 3 is used to control the high voltage from the T901 flyback
9. 57 Ibs 5 oz DDC1 DDC2B DDDC2Bi GTF Power Saving 4 Power Modes 3 power saving Normal 140Watts Standby 15 Watts Suspend Sleep 15 Watts Active Off 6 Watts Circuit Protection 200 Flyback Voltage Vertical Output Automatic Beam Current Limiting ABL Plug and Play Abbreviations Level Name Communications DDC1 Display Data Channel PC reads monitor EDID Uni directional data Operational info V sync intervals Protocol V Sync Display Data Channel PC reads writes monitor Bi directional data EDID operational info Protocol Bus DDC2B DDC2Bi PC reads writes monitor EDID operational info And adjustment data Protocol Access Bus Display Data Channel Bi directional data NOTES Normal Operation Features Power ON Initial Conditions No video input 120Vac input Cold start 1 Press power ON switch 2 Front panel indicator LED is green 3 Degassing coil receives AC current causing the picture tube s aper ture grill to vibrate humming sound The AC surge current is about 6 AC amps Current drops down to 0 6 AC amps The following black lettered graphic appears at the center of the screen with strips of the color indicted INFORMATION NO INPUT SIGNAL INPUT 1 WHITE RED GREEN BLUE Active Off Low Power Mode no input 1 Two minutes after pressing the power ON switch the monitor auto matically ent
10. Symptom Ghosts or shadows the picture Excessively long cables going to the computer or a loop through box is used to run more than one monitor 7 Symptom Retrace lines present in the picture G2 voltage is too high b Cut off control driver IC or support parts are defective Check all volt ages about the cut off control IC and compare them to the voltages listed in the schematic vi 8 Symptom Intermittent cut off control IC failure Arcing in the CRT can cause repetitive failure of this cut off control IC and zener diodes that protect the RGB signal from the Output IC 9 Symptom Can only focus in the center or at the sides but not both The dynamic focus circuit is not working Look for a loss of focus wave form in this circuit 10 Symptom Front panel pushbuttons have no effect One of these buttons is shorted on and locking out the others Liquid food is solidified holding a button in 11 Symptom Two thin black lines are always on the CRT They never move These damper wires in the CRT are necessary for support These very thin horizontal lines are normal in a high quality Trinitron picture tube Damper wires 12 Symptom Picture remains readable only during boot up Sync is lost after entering a Windows program a The software from the computer is instructing the graphics card to output sync at a higher or lower frequency than the monitor s normal operating range b The plug
11. amp Vert video Blanking RGB Cutoff Normal Display Sets CRT cutoff voltage level 004 OSD Menu Measures Ik cathode voltage Aging Ik image restore DC Voltages Aging Mode The RED cathode was unsoldered for measurement comparisons Red drive voltages are unaffected but Ik voltages are lower Troubleshooting See the troubleshooting checklist in the appendix portion of this training manual Function Location Red Green Blue RGB signal Input 1 001 10 12 1 9V 1 9V 1 9V to IC001 no signal is input in the aging mode RGB signal Output ICOO1 pins 20 23 2 7V 2 7V 2 7V from 1 001 27 RGB Background 1 001 30 32 3 8V 3 7V 3 2V Output from 1 001 Background Out RGB Output from 02 5 5 7 43V 43V 43V 002 Background Input 1 004 13 15 4 77V 4 7V 4 6V at IC004 Background IC004 pins 3 5 amp 111V 110V 101V Output from 1 004 7 Output from IC004 pins 10 12 0 35V 0 507V 0 53 1 004 Input to 1 003 003 20 22 1 1 95V 2V OSD Output from ICOO3 pins 14 16 0 16V 10 16 0 16V 1 003 R OUT FROM 1 008 27 30 355 G OUT RGB OUT LM24026 B OUT B 11C FROM 1 1001 36 37 SDA D BD SCL CONT 3 H8D2972 7 5 0108 128 108 5 0 1 1k ji 25V p Gee R115 270k FILT FILTER V SYNC 1001 26 H SYNC 1 1001 27
12. 1 1KV Waveshape TIC cen Location CN1006 pin 2 CN1006 pin 4 Ld CN1006 pin 13 Q504 Gate Q504 Drain Q505 Base Q505 Collector Measured without the computer connected to the monitor no sync The monitor is set in the Aging Mode or the measurements are made before the unit enters the power save mode The CPU s horizontal output is always present even in the Active Off power saving mode Sweep Width Compensation Circuits The basic left to right sweep duration is set by the DPU but its final sweep width and linearity is different for each horizontal frequency As this 55 main sweep H drive signal is processed it passes through L C induc tors and capacitors and the deflection yoke H DY Since the output of the L C components in the drive path will change with frequency com pensation circuits are needed These circuits make sure the sweep will be a uniform length and position at all operating frequencies Pincushion compensation circuit S Capacitors for width compensation circuit Centering compensation circuit Failures such as insufficient width poor linearity and shutdown do occur in this stage but are difficult to pinpoint since that operating frequency mode must be duplicated The complaint is usually intermittent monitor failure shutdown or width reduction Testing Each mode can be simulated by selecting it from the DAS Control Signal G
13. Input Vertical 5Vp p negative Sync On Green Path This method of supplying vertical and horizontal sync on the green video signal line to the monitor is still popular today simply because there are less connections to make 002 and Q003 remove the vertical and hori zontal sync from the green video signal Horizontal Signal input levels Sync polarity 5Vp p negative The transistors are pre biased to buffer Q002 and permit only the nega tive sync pulse part of the signal to be amplified Q003 The output of this sync separator stage is 5Vp p positive polarity H amp V sync pulses that are applied to 1 1001 28 If Vertical and horizontal sync are detected at IC 1001 pins 20 and 30 the sync on green input at pin 28 is disregarded Sync On Green Input Signal Location Voltage Green input with negative sync Q002 base 1Vp p Green input with negative sync Q002 emitter 1Vp p Q003 base Positive going H amp V sync Q003 collector 5Vp p STANDBY 45V 006 INVERTER BUFFER TC74HCTO4F V SYNCO TO 1 DPU 1 801 42 N BD 2 OSD 003 6 H OUT A BD 009 4 V OUT 009 14 gt 10012 CPU STANDBY CDX9523S 5V 4 1V lt R078 C063 42 Q003 H SYNC TO q TE IC801 44 4 7V R082 N BD R081 ii 29080 1 003 5 1 009 15 R051 Q002 SYNC SEP A BOARD D BOARD
14. LCD displays the voltage reversal is performed at the end of the field for next field vii RGB Pixel Control There are various ways the pixels in an LCD panel can be controlled In model CPD L181 A D Converters convert the analog RGB signal to digi tal format bus CPU 1 1407 A D Converter Memory R AID Controller Converter A D Converters amp Mem Controllers B Sync Sync Sep IC504 PIVS PIHS The A D converters output a differential digital signal to the memory con troller The memory and the memory controller store the video informa tion so the correct color pixel can be turned on at the right time The old and new voltages to the LCD display correspond to the 8 bit address location of each pixel and the voltage applied brightness to that pixel The memory controller requires digital video information sync a very high speed clock for pixel selection as well as data amp clock communica tions from the CPU Backlight The two fluorescent backlights labeled LCD in the service manual are used in model CPD L181 Each backlight is fed a high frequency AC signal from its corresponding preassembled inverter board A fan is re quired to keep the backlights cool Service Position Warning When repairing any electronic product DO NOT PLUG THE PRODUCT DIRECTLY INTO AC Plug the product into an isolation trans former and the transformer into AC to reduce damage and the danger to you when
15. Q001 base 8 46V Buffer output G2 Q001 collector 660V Brightness reduction 0006 0 35V Reduction control Q006 emitter 0 75V Voltages taken in the Aging Mode within 5 mins after turn On Normal Operating Voltages after 1 2 hour in the Aging Mode Location Q001 collector Q006 base Q006 emitter Name Buffer output G2 Voltage 667V 4 2V 1 9V Brightness increase Increase control G2 amp Cathode Voltage when Blanked no video input Location Normal Pix Blanked G2 CRT pin 667V OV R G or B cathode pin 80V 15V 11C DATA CLK BUS 1 1001 CPU 95235 G2 CONTROL 48 1 005 G2 CUT OFF NJM2904M 9MONOA 1216 1 18 00 Sync Deflection Block Several stages can be grouped together to provide the CRT with basic operating signals These stages run independent of the video circuitry and are self sustaining The main stages in this block are Deflection Block Stages Function CPU 1 1001 Horizontal amp Vertical Oscillator Protection circuit Data control DPU 1 801 e H amp V waveform shaping for each monitor mode e Pincushion correction signal e Picture rotation Dynamic Focus e Convergence signals High Voltage Generation and regulation Horizontal Deflection CRT beam sweep left to right Pincushion Corrects for black left and right bowed areas Vertical Defection CRT beam sweep top to bottom CPU 1001
16. Symptoms Video Block Input Video Output G2 Control CRT Brightness G2 Circuit 17 17 19 19 21 21 23 23 25 25 29 31 31 31 33 35 37 39 41 47 47 47 Circuit Voltages Sync Deflection Block CPU 1001 amp DPU 801 Horiz Vert Oscillator Vertical Output Horizontal Output High Voltage HV Manufacture HV Regulation Protection Troubleshooting Dynamic Focus Concept Static Focus Dynamic Focus Dynamic Focus Circuit Horizontal Dynamic Focus Correction Vertical Dynamic Focus Circuit Digital Convergence Self Diagnostic Function 47 49 49 51 53 55 57 57 57 59 59 61 61 61 63 63 63 65 67 Appendix Power MOSFET Tests or Bus Data Format Plug and Play Monitor Problems Checklist LCD Concept Service Position NO High Voltage Testing Position Full Operational Testing Position vii viii viii Trinitron Picture Tube Viewable Area Standard Image Area Maximum Resolution Deflection Frequency AC Input Operating Temp Mass Plug and Play 1 Sony Monitor Model CDP G400 Specifications 0 24 mm aperture grill fine pitch 19 inches measured diagonally 90 degree deflection low distortion 14 3 8 x 10 7 8 18 viewable image 13 7 8 x 10 1800 dots Horizontal 1024 dots Vertical 30 to 107 kHz Horizontal 48 to 120Hz Vertical 120V AC 50 60 Hz 140W 1 17amps 6 Amps initial surge measured 10 to 40 degrees C
17. and Gate are the outer leads on this TO 220 case FET Q902 Q901 G S Surge Relay RY602 Degauss Relay RY601 3 Disable SCR D616 by shorting diode D617 nearby D617 is con nected to the SCR s gate and cathode 23 0617 G D616 SCR A Keep the Yoke connected to the D board CN1 to CN501 so the unit will not go into ABL shutdown Keep the A board connected at CN306 CN309 and CN31 1 for CPU communications and power Apply external 5Vdc in series with a diode to IC605 pin 1 This turns ON 5V regulator IC605 and 12V regulator IC604 You may want to place a diode in series with the external 5V power supply to prevent damaging your test equipment Use the shield as a cold ground Al ternate procedure If you do not want to use an external power supply the monitor will normally enter the Active Off Mode after one minute At that time press a front panel mode button to return the Monitor to the Normal Power Mode Press the power ON button and the monitor s power supply will come up in the Normal mode and remain in that mode After one minute without sync input the CPU will turn ON the front panel Orange indi cator butthe monitor voltages are active except for the final HV Heater voltages and FBT voltages R627 R693 4 7M 4 7M VIN 4 OOB 5 6V IC603 dos SW REG CONT TEA1504 SENSE 9 V CONTROL 6 VAUX at R643 6135
18. and bottom Although the dynamic focus correction circuitry is an independent pro cess the same IC801 DPU makes the vertical and horizontal dynamic focus correction signals The separate VDF and HDF outputs feed indi vidual amplifiers before being capacitor coupled to the static DC focus voltage at the flyback transformer T901 Horizontal Dynamic Focus Correction The main input needed by 801 to construct the horizontal dynamic cus signal is the flyback pulse HFBP at CN1006 pin 15 The vertical sweep signal VFBP at CN1005 pin 11 is also needed for additional cor rection when the beam is at the corners of the screen The DPU 10801 uses both of these inputs to make a HDF signal that leaves the N board at CN1005 pin 14 The HDF signal is amplified and inverted by Q701 Q705 Transformer T701 couples the signal to the flyback s static focus voltage for horizontal focus correction Horizontal Dynamic Focus Signals Name Location DC AC Wave Shape HDF CN1005 14 1 81V 0 8Vp p Q701 base 1 25V 0 8Vp p Amplified Q701 23 2V 44V p p collector T701 pin 2 24 2V 44V p p RASS HDF signal All voltages and wave shapes taken in the Aging Mode 63 Amplifier Stage DC Voltages Emitter Base Collector Q701 0 6V 1 25V 23 2V Q702 24 5V 24 8V 77 1V Q703 23 7V 23 1V OV Q704 24 2V 24 5V 77V Q705 24 0V 23 75V OV
19. and play DDC communication is defective This serial com munication from the monitor tells the computer what frequencies the monitor is capable of As a result the computer s video card should not generate a frequency beyond this range to cause this problem LCD Concept Basic Pixel Structure The pre assembled LCD panel contains thousands of crystal lized electro chemical structures one for each pixel Each structure either blocks or passes light Transparent membranes at the front and back of the blocks apply voltage to the struc ture much like a capacitor No Light Backlight when voltage is Pixel applied es When voltage is applied across the structure the crystals within will misalign and the structure blocks the backlight dark pixel The greater the volt age the darker the picture is Placing a red a green or a blue filter in front of the pixel to pass that color from the backlight creates color A set of three different color pixels is placed in a delta array pattern on the LCD screen White is output when the backlight shines through all three filters and the eye perceives the area as a white light When voltage is applied to the pixel for a prolonged period there is chemical degradation To avoid structural failure the voltage across the pixel is reversed periodically Therefore the voltages at the pixel are both float ing above ground so there is a great deal of activity on these drive lines In most
20. button was pressed CPU 1C1001 discontinues the HIGH from pin 5 so the degaussing relay contacts open removing power from the degaussing coil CPU 1 1001 5 will remain LOW as long as there is standby 5V applied to it power switch is ON 10 Surge Protection Circuit At power ON this monitor consumes power in two places Degaussing coil circuit About 6 AC amps Monitor power supply About 0 5 to 1 amp depending upon the charge of the filter capacitor C611 The surge protection circuit reduces the amount of power and voltage fluctuations to the monitor s power supply until the degaussing circuit has completed its task This is accomplished by placing a current limiting resistor thermistor TH600 in series with the bridge rectifier D625 1 8 sec after the power button is pressed the current limiting resistor is jumped out of the circuit 19 The sequence of operation is as follows 1 2 3 B Power ON button is pressed Heavy current goes to the degaussing circuit The monitors power supply is current limited by TH600 6 5 ohms cold Although delayed the power supply voltages come up 15V is one of the power supply voltages This voltage is applied to the surge protection circuit at RY602 and C635 via R671 At 15V C635 takes about 0 2 milli seconds to charge to 8 6V Zener diode D627 conducts turning ON Q607 Q607 in turn energizes the surge relay RY602 RY602 s contacts jumper short
21. dark picture failure poor focus and or blooming the sides but not both 4 A color is too weak or 10 Front panel pushbuttons have no bright effect 5 One or more colors flicker intermittently on the CRT They never move 6 Ghosts or shadows in the 11 Two thin black lines are always 12 Picture remains readable only during boot up Sync is lost after entering a Windows program picture 1 Symptom Green power light ON but no picture screen dark Unlike TV sets monitors will normally remain dark blanked unless there is horizontal and vertical sync input the monitor from the computer Many things are possible a b First try a different computer Look for CRT filament glow through the vent holes and shielding At the CRT socket with the computer connected and running look for G2 screen voltage approx 400 1kVdc This voltage comes from the high voltage Therefore if you have normal screen voltage you also have high voltage If the G2 screen voltage is only at B level there is probably no high voltage Warning The danger is that if you have NO G2 voltage you can still have high voltage because of a defect in the G2 control circuit or an open path from the flyback e Filament voltage 6Vdc 6Vrms or B voltage Should be less than 200V to produce bright ness e Focus voltage Aloss of focus voltage will not cause a dark screen but
22. loads e Standby 5V is missing or CPU is defective e SCR D616 is shorted e The regulating circuit is defective If you cannot find a short in one of the power supply loads or FBT loads you can force the power supply to enter the Normal mode This is done by e Disabling the HV for your own safety e Disabling the SCR on the 200V line e Turning ON the 5V and 12V regulators A service manual to locate the parts a jumper wire to force the power supply into the Normal Power Mode and a 5V power supply is needed to turn on the regulators Warning When repairing any electronic product DO NOT PLUG THE PRODUCT DIRECTLY INTO Plug the product into an isolation trans former and the transformer into AC to reduce damage and the danger to you when servicing R627 R693 4 7M 4 7M VIN 4 OOB 5 6V IC603 dos SW REG CONT TEA1504 SENSE 9 V CONTROL 6 VAUX at R643 613522 OHMS 47 R644 100 REGULATOR CIRCUIT R615 33 OHMS SWITCHING OSCILLATOR 26 pets HG 80V 5V HEATER TO CPU CPU IC1001 8 04 1198 1 28 00 The procedure is as follows 1 Position the main board to access the power supply You will not need the picture tube nor degaussing coil You will need the 5 volt loads on the D board and the CRT s A board Disable the HV by shorting Q902 s Source and Gate leads Q902 is on the large heat sink on the main D board near the relays The Source
23. no high voltage will The focus voltage is a function of the high voltage and another indication HV is present Therefore if there is focus voltage there is high voltage Focus voltage may be difficult to access in some sets 2 Symptom Very Dark Picture In older monitors a bad CRT will display a dark picture accompanied by poor focus In newer monitors a b Check the drive signal level from the computer by substituting another computer Measure the CRT filament voltage with the CRT connected It will be 5 5 to 6 if the voltage comes from the LV power supply or 6Vrms ifthe voltage comes from the flyback Inspect the CRT socket pins for corrosion white powder and clean or replace the socket Compare the G2 voltage at the CRT with the voltage in the service manual An abnormally low voltage will reduce brightness The typi cal G2 voltage varies with screen size Compare the voltage at the CRT R G or B terminals to the service manual voltage The voltage will be a function of the input signal so it will be different A lower voltage causes a brighter color The average voltage at these or B CRT terminals is stored in memory retrieved by the CPU and transferred to the RGB cut off control IC via serial data 3 Symptom Very dark picture with poor focus and or blooming Old monitor CRT is weak New monitor High voltage is unregulated or low Break in the CRT filament connections at the socket o
24. only powered up in bursts As a result all the monitor supply voltages are Low or absent depending upon the severity of the load There is sufficient energy to power standby regulator IC609 not shown to the CPU This is because the CPU needs little current so the standby 5V is normal while the remaining voltages to the monitor are extremely low In this Active Off power mode the green and orange LEDs are both ON as in the suspended power mode The difference is that in the Active OFF mode the 15 from the power supply is no longer active and the surge relay can be heard de energizing as it enters this mode Power Mode Summary Six seconds after the monitor is powered ON the degaussing circuit relay de energizes A display then appears showing the video input status After one minute the monitor will enter one of four power modes if sync is missing The CPU monitors video input sync to implement the power mode Monitor Power Modes Power Mode Cause Green LED Indicator Orange LED Indicator Audible Indicator 1 Normal H and V sync input to the monitor OFF Surge relay energizes one second after pressing the power ON button 2 Standby No Horizontal sync Blinks None 115 ac mA 3 Suspend No Vertical sync ON None 115 ac mA 4 Active Off No Vertical or Horizontal Sync ON ON Surge relay de energizes 60 seconds 52 ac mA after pressing the power ON switch FROM INPUT 1 FROM INPUT 2 POWER SUPPLY 5
25. power modes 1 Normal All voltages are operational 2 Standby 5V 8 12V regulators OFF screen blanked No H sync input Suspend 5V amp 12V regulators OFF screen blanked No V sync input Active Off All power supply voltages very low except standby 5V to CPU amp V sync Regulated voltage to filaments Switched Off in the Active Off Mode Heater Regulator 13 Power Supply Output This power supply has outputs that are fused and unfused Fused Switching Power Supply Outputs Voltage Fusible Resistor Destination 6 5 R649 R650 Horiz Centering 15V R648 Drive Q504 Rotation Drive IC703 Vert Out 1 401 Converge Amp 1 701 IC702 15V R645 12V Regulator IC604 Surge relay RY602 Rotation Drive IC703 Vert Out 401 Converge Amp 1 701 1 702 8V R647 Heater Regulator 1 610 Sw 5V Reg IC605 Standby 1 609 Reg Circuit Q609 Unfused Switching Power Supply Outputs Voltage Destination 200V Active Off Switch D616 RGB Cutoff Control 1 004 Pin Out Q506 HV Regulator Q901 CPU 1001 14 80V RGB Output IC002 Dynamic Focus Circuit Q704 5 Active Off Low Power Mode When the computer connected to the monitor is shut off horizontal and vertical sync input signals stop CPU 1001 senses this loss and turns off both the Remote ON OFF and Heater output lines The Remote ON OFF line
26. power supply the LOW will change into 5Vdc without a waveform This proves the IC901 regu lator is OK The remaining parts in this regulating loop that must be manually checked or replaced are D913 16V zener RV901 100k ohm HV control measures 53k ohms adjusted The circuit foil path between FBT T901 pin 17 and IC901 can also be checked when the external power supply is connected to D916 C Just check for voltage at destination T901 pin 17 200V Q901 HV SW IRF19634 HV CONT BA9758FS HV DET 1 1001 16 HV GENERATION REGULATION 60 0901 0902 ARE SHOWN DIFFERENT THAN SERVICE MANUAL HV TO PIX TUBE 77 FC 5 DF INPUT ABL DET 1 1001 17 1 901 12 832 8 2k 13MONO4 1211 1 19 00 Dynamic Focus Concept Static Focus An electron beam within the picture tube consists of many electrons that are slowed down by the focus electrode After passing through the focus electrode the accelerating electrode brings the beam to a fine point on the screen This focus point is positioned by adjusting the voltage at the focus electrode relative to the accelerating voltage The accelerating volt age is usually fixed at the HV potential from the flyback secondary CRT Electrodes Focus Accelerating Focus Electron beam Picture Tube Electron Beam As the electron beam is moved from side to side swept by the magnetic field created by the external horizontal deflec
27. transformer IC901 s PWM output directly controls the conduction time of switching MOSFET Q901 ALOW going pulse applied to its gate turns on Q901 When Q901 is turned ON voltage is applied through T902 to HV Output transistor Q902 Drain to serve as The longer Q901 is turned ON the higher the voltage is at Q902 As Q902 s B increases so does its gain and the T901 flyback voltage HV L H 0 ve ALT 2 00 0 1 901 Waveforms Aging Mode Name Location Voltage div Channel 1 H Drive input IC901 pin 14 10Vp p Channel 2 PWM Output 901 3 10Vp p Channel 3 MMV Output IC901 pin 5 10Vp p Time base 2usec div The pulse widths will be different when sync is input the monitor HV Regulation HV regulation is accomplished by controlling the B applied to Output MOSFET Q902 Drain This is done using 1 901 and Q901 in a closed loop regulation system 1 901 samples the flyback output voltage at T901 pin 17 This voltage is returned to IC901 pin 11 for comparison to a 9V reference at pin 12 The LOW going pulse that is output IC901 pin 3 is changed in width based upon this comparison A wider LOW going pulse 200V Q901 HV SW IRF19634 HV CONT BA9758FS HV DET 1 1001 16 HV GENERATION REGULATION 58 0901 0902 ARE SHOWN DIFFERENT THAN SERVICE M
28. 0 REGULATOR CIRCUIT R615 33 OHMS SWITCHING OSCILLATOR 24 pets HG 80V 5V HEATER TO CPU CPU IC1001 8 04 1198 1 28 00 Mode Switching By using three operating modes to maintain the output voltages the power supply is more efficient The correct operating mode is selected by IC603 pin 14 for the Active Off Mode and maintained by using feedback from transformer T602 pin 2 This signal is reduced considerably by R635 as seen in the next waveform 42 0 v BRL LESE aa Mode Sensing Name Location Voltage Channel 1 Feedback T602 pin 2 D613 A 30Vp p Channel 2 DEM IC603 pin 13 5Vp p Time base 2usec div Operating Voltages 1 603 DC Voltages Pin Stby Mode 2 5V 0 0 06 0 2V 11 4 12 5V 12 2V rp a lt 25 Power Supply Output Voltages Line Location Normal Light Mode Active Off Mode 200V Q D614 C 200V 16 5V 80v D618 C 77 5V 6 82V 15V D619 C 14 9V 1 07V 9V D620 C 8V 1 75V 9V D621 C 9 2V 13 5V for CPU 15V D622 A 14 8V 1 2V V D623 C amp 6 5V 1 1V D624 A Forced Normal Operating Mode If the power supply will not enter the Normal Operational mode stays in the Active Off Burst Mode this is because e There is a short on one of T602 or FBT secondary
29. 12 INPUT 1 2 ON OFF SEL SW HEATER 1 1001 CPU STANDBY 5V POWER SAVING CIRCUIT 10 5 4 1205 1 19 00 Power Mode Circuit Activity The front panel combination green orange LED identifies the lack of H or V sync input The monitor power operating modes relating to the circuitry is summarized this chart 11 Monitor Mode Details Power Mode Power AC Power Video Main CRT Surge Resistor 5 Standby 1 1001 Indicators Consumption Blanking Power Heater Bypass Relay Regulator 5 CPU input minute Supply 610 602 605 1 609 1 Normal Green 140W 1 16A Unblanked Active Active Relay energized Regulator Active H amp V input Nominal Surge Resistor ON sync to 6 amps bypassed 2 Standby Green ON 15W 0 115 A Blanked Active Active Relay energized Regulator Active No H sync Orange measured Resistor OFF input blinks bypassed 3 Suspend Green ON 15W 0 115 A Blanked Active Active Relay energized Regulator Active No Vertical Orange ON measured Resistor OFF Sync input bypassed 4 Active Green ON 3W 0 052 A Blanked Bursts OFF Relay OFF Regulator Active No Vertical or Off Orange ON measured only OFF Horizontal Sync POWER SUPPLY SURGE RELAY RY602 ORG K BURST 200V MODE STBY 1 1001 0 95235 11 DET DET 11C CLK
30. 14 to only regulator 1 609 1 609 powers the CPU IC1001 The SCR is reset because there is insufficient current to keep it latched Light Mode From the Active Off mode the monitor can return to the ON mode when input video sync is detected or if a front panel input has been selected Both inputs are monitored by the CPU The CPU discontinues the SCR Heater signal and turns ON both regulators The regulators immedi ately load the power supply stage The decrease in peak to peak feedback voltage from T602 pin 2 causes IC603 to power 1C603 first eliminates the bursts and provides a con tinuous oscillator signal from pin 4 Light Operating Mode If the Light Operating Mode does not bring the secondary voltage up fast enough IC603 increases the frequency and pulse width to meet the power de mand normal mode When the power demand is minimal such as in screen saver or a front panel input in triggered with no video input the power supply may choose the Light operating mode The monitor current is measured at 5 In this light mode the power supply does not have to work as hard to maintain the secondary voltages that are used to drive the monitor As a result the oscillator frequency is only 26KHz in the light mode instead of the normal 63kHz R627 R693 4 7M 4 7M VIN 4 OOB 5 6V IC603 dos SW REG CONT TEA1504 SENSE 9 V CONTROL 6 VAUX at R643 613522 OHMS 47 R644 10
31. 15 4 1217 1 19 00 HORIZ VERT OSCILLATION PATH 52 Vertical Output Vertical Stages The vertical stage consists of three ICs IC IC Number Location Function Name CPU 1 1001 V Oscillator free runs at not behind bezel 80Hz or locked to input shown sync CRT protection Monitors V Output voltage VFBP DPU 10801 Small board V Drive on the D Sets vertical size saw board amplitude Limited range DC centering Vertical IC401 a heat sink Vertical Amplifier Output nearthe FBT Vertical Flyback voltage boost circuit is monitored by the CPU for protection Vertical Oscillator CPU 1 1001 houses the vertical oscillator It runs as long as there is Standby 5V applied The vertical oscillator free runs at 80 Hz and is locked to sync when input from the computer 53 1001 Inputs Outputs CPU 1 V Sync not required Oscillator output 60 IC1001 for an output 5Vp p 2 Standby 5V 3 8Mhz Xtal 4 VFBP V output signal for shutdown protection Vertical Drive The 1 801 serves as the vertical driver Input are positive vertical pulses and output are sawtooth pulses and a DC reference voltage DCC2 The sawtooth signal is also used for convergence and geometry control within IC801 not shown IC 801 Input Oscillator pulses Serial data amp clock Vertical Output This output amplifier amplifies the signal and supplies
32. 22 OHMS 47 R644 100 REGULATOR CIRCUIT R615 33 OHMS SWITCHING OSCILLATOR 28 pets HG 80V 5V HEATER TO CPU CPU IC1001 8 04 1198 1 28 00 Switching Oscillator Part Functions Defective Parts Purpose of Parts Power Supply Parts Functions Possible symptoms 0609 C612 Q605 Protection Immediate Q605 failure C610 C617 D611 C619 R640 R641 Q605 Protection Q605 Protection Intermittent Q605 failure Power supply oscillator stops R630 open no error signal Error detection circuit Power supply cycles between Normal and Active Off Modes R632 R633 D612 18V zener Oscillator frequencies off C603 protection Blooming Q605 gets too hot Monitor dead Repeated failure of 1 603 and Q605 D613 R642 D633 Standby 5Vregulator for CPU R693 R627 Powers IC603 CPU power Oscillator Starting Oscillator at 603 4 starts for a few cycles and stops Monitor momentarily powers up then enters the Active Off mode Monitor dead 29 R627 R693 4 7M 4 7M VIN 4 OOB 5 6V IC603 dos SW REG CONT TEA1504 SENSE 9 V CONTROL 6 VAUX at R643 613522 OHMS 47 R644 100 REGULATOR CIRCUIT R615 33 OHMS SWITCHING OSCILLATOR 30 pets HG 80V 5V HEATER TO CPU CPU IC1001 8 04 1198 1 28 00 Low Voltage Regulating Ci
33. ANUAL HV TO PIX TUBE 77 FC 5 DF INPUT ABL DET 1 1001 17 1 901 12 832 8 2k 13MONO4 1211 1 19 00 will increase the HV This LOW going pulse is applied to switching MOSFET Q901 s gate The longer the LOW going pulse duration the longer Q901 stays turned ON As Q901 stays ON longer its output volt age increases This results in a higher voltage for Q902 that increases the HV from flyback T901 The regulating loop is closed when 9V from the FBT T901 pin 17 is ap plied to IC901 pin 11 A lower input voltage at pin 11 will cause Q901 to conduct longer and increase the B and corresponding flyback voltage until T901 pin 17 is at 9V again RV901 adjusts the voltage at 901 11 and consequently the HV In the aging mode the HV is set to 27kV 40 2 Protection IF the regulating is defective and the flyback voltage rises too high the CPU will enter the low power Active OFF Mode for protection The CPU monitors the 300 flyback output at T901 pin 8 via zener D912 to detect excessive HV Normally there is 19V at D912 cathode and 3V at D912 Anode 16V zener Excessive HV causes the cathode voltage to rise proportionally If the cathode rises to 21 volts the CPU IC1001 pin 16 will receive a trip voltage of 5V to activate the Active OFF Mode for protec tion The front panel LED will blink at a 1 Hz rate to indicate excessive HV has caused the monitor shutdown Troubleshooting Ch
34. ING POWER SUPPLY OP ISOLATE TLP621D4 MAIN ERROR REGULATOR CIRCUIT 200V SOURCE 0615 2W 667 47k2 Res 9606 HEATER FROM 1 1001 8 STBY 45V 2 5V R682 R676 608 SHUNT REG TL1431 VOLTAGES 681 C644 WERE 0 05 MEASURED IN THE NORMAL POWER MODE 1 L V REGULATOR CIRCUIT 6 04 1202 1 24 00 34 1 607 Isolator 1 in 2 gnd G D616 SCR 3 out 5608 5V Regulator Simulated Defects and Symptoms Simulated Defects Symptoms Cause Troubleshooting Picture is dim or dark All LV PS voltages are low 200V 145V 1 Short or excessive load in T602 s secondary winding 2 No DEM feedback voltage to PS oscillator Measure all secondary voltages The one that is very low is being loaded down If they are all proportionally low 603 13 DEM is not getting feedback signal Green LED flashes PS oscillator chirps as it powers up and shuts down Power Supply voltages are high The regulation loop is open Test D616 for shorts and disable if good by shorting G K Measure voltages in Regulation Correction Path chart to see what voltage does not change while the oscillator is chirping 35 Green LED is ON Only the standby voltage is pres
35. KE VSAWIN PROTECT 3 1 1001 16 04 1220 1 19 00 Deflection Support Stages Video Processing Block Stage Parts Function Stage Parts Function Dynamic IC1001 Oscillator signal for beam location Input Switch 1 008 RGB input switch Focus C801 Signal shaping 009 Sync input switch Q701 5 Horizontal dynamic focus amp RGB Amp 1 001 Preamp of the input signal 1 503 Q706 Vertical dynamic focus amp Output 1 002 Higher voltage amplifier Pincushion 1 1001 Oscillator signal for beam location OSD 1001 Selects OSD pattern based upon user 801 Signal shaping selection 0506 Q508 9 Amplifier and output driver IC003 Generates the OSD picture graphic Convergence signal for beam location DAS Control An external alignment computer controls many parts the monitor s align IC701 Static convergence amplifier ment The alignment is achieved using a special computer to monitor C702 Dynamic convergence amplifier communications connection on the D board The 4 pin internal jack con nects to the monitor s CPU 1 1001 High Voltage The high voltage block uses a flyback transformer and some of the later horizontal deflection circuits This block s primary purpose is to develop and maintain the high voltage for the final beam acceleration across the picture tube bell Two additional high voltages are also made from the flyback T901 The static focus voltage is us
36. SONY Computer Monitor F99 Chassis CPD G400 Circuit Description and Troubleshooting Course MON 04 Training Manual Sony Service Company A Division of Sony Electronics Inc 1999 All Rights Reserved Printed in U S A SONY isatrademarkof Sony Electronics Circuit Description and Troubleshooting Model cpp G400 F99 Chassis Prepared by National Training Department Sony Service Company A Division of Sony Electronics Inc SONY SEL Service Company A Division of Sony Electronics Inc 1 Sony Drive Park Ridge New Jersey 07656 40200 Printed in U S A Sony Monitor Model CPD G400 Specifications 1 Normal Operation Features Power ON Power OFF Aging Mode Lock control S RGB Customer Convergence Moire Adjustment Reset All User Adjustments Reset Just One User Adjustment Self Diagnostic Function Overall Block Power Supply Deflection High Voltage Video Processing Power Saving Modes Power Mode Summary Power Mode Circuit Activity Power Supply Block Degaussing Surge Protection d o 200 000 5258252 5 2 0 Table of Contents AC Input Degaussing Circuit Surge Protection Circuit Operating Voltages and Resistances Switching Oscillator Start Up Normal Mode Active off Mode Light Mode Mode Switching Operating Voltages Switching Oscillator Part Functions Low Voltage Regulating Circuit T602 Feedback The Regulator Circuit Measured Voltages Simulated Defects and
37. Vertical Dynamic Focus Circuit The vertical dynamic focus correction signal is made in DPU IC801 using vertical and horizontal sweep signals from CN1005 pin 11 and CN1006 pin 15 The simple parabola shaped VDF correction signal is amplified by 1 503 and driver Q706 The resultant 200V VDF signal is capacitor coupled to the FC focus voltage inside FBT T901 pin 15 Vertical Dynamic Focus Signal Path Location DC AC CN1005 pin 15 1 8V 1Vp p Q706 base 4 9Vp p Q706 emitter 3 5V 9Vp p Q706 collector 145V 200Vp p All voltages and wave shapes taken in the Aging Mode Troubleshooting When you are only able to focus the monitor at the center of the screen and not the sides or corners the dynamic focus stage is not working In all operating modes of this monitor HDF and VDF signals will be output from 1 801 Trace these signals to the FBT T901 Note If you disable the HV short Q902 G S for signal tracing the 300V and the final VDF signal at Q706 Collector will not be present 753 10 5 80V gt 0701 12 70703 JOUT 2 1 401 7 P A R747 D BD HoRIz 900V 2 12V DYNAMIC CN1006 CN801 r zm VFBP CN1005 N BOARD 720 VOUT 908 0 01 1 1001 36 37 DYNAMIC FOCUS CIRCUIT 14MONO4 1215 1 19 00 64 65 Convergence Output Waveform Digital Convergence Circuitry Using data stored in the EEProm m
38. age Sensed at 1001 Normal IC1001 Trip Power Mode Latched 1001 Voltage Voltage Only the Green LED blinks at 200V excess N A N A N A PS restarts N A about 2 Hz Both LEDs are dark PS beeps B shorted N A N A N A PS restarts No 2 Hz Both LEDs blink at 1 Hz HV Detection Pin 16 2 8V 5 0V Active Off Yes Both LEDs 2 sec OFF 1 V Output H Output Pin 42 3 3 0 6 Active Yes sec Both LEDs blink ON 1 sec ABL CRT current Pin 17 5 0V 5 2 Active Off Yes OFF 2 sec LEDs alternately blink 1 sec None Aging Mode each Detection 200V is sampled by the CPU 1 1001 14 but the CPU is not pro grammed to respond Perhaps this is because the monitor is well pro tected at the power supply itself where the power transformer s second ary is fed back directly to the control IC A higher voltage will cause the power supply control IC to momentarily stop the oscillator The oscillator will start again causing the front panel green LED to cycle on then off then on repeatedly as the power supply switches on and off See the Regulating Circuit for details HV Detection This monitor uses the Horizontal pulses from the DPU IC801 N Board a regulating circuit and the FBT T901 to make HV CPU IC1001 pin 16 monitors a winding of the flyback at T901 pin 8 for excessive voltage Excessive HV causes the CPU s Heater output voltage to be LOW caus ing SCR D616 to trip the power supply into th
39. amp 1 801 When the monitor is turned ON the horizontal and vertical oscillators inside the CPU IC1001 produce an output These oscillators run at de fault frequencies of 70kHz and 80Hz respectively until sync is input to change these two frequencies The DPU 1 801 shapes the horizontal signal into the correct pulse width picture size and the vertical signal into the correct ramp size and linearity High Voltage The HD signal from the DPU IC801 is used for horizontal sweep and high voltage generation The HD signal is amplified and buffered in the drive stage 0501 0503 before being spit into two paths The first path is into the High Voltage stage IC901 Q901 2 This stage uses the horizontal signal to generate high voltage The high voltage level is regulated using 49 a sample of fly back FBT T901 voltage The fly back causes the remain der of the voltages for the CRT to operate The CPU uses a sample of the HV voltage and ABL voltage CRT current from the FBT for protection The CPU will latch the monitor into the low power mode when there is excessive voltage or current Horizontal Deflection amp Pincushion The Horizontal Output stage Q504 uses the amplified HD signal to pro vide sufficient sweep to deflect the electron beam across the CRT screen The CPU monitors the output in case of a sweep failure protect and enters the low power mode without a sweep signal The H Shape signal from the DPU IC801 is used
40. and IC609 are used to maintain standby 5V for the CPU CPU 1 1001 activates the Active Off reduced power mode when both horizontal and vertical sync inputs are missing computer OFF The CPU IC1001 pin 8 LOW turns OFF the CRT heater and Q606 after the loss is detected The path used to enter the Active Off Mode and for Standby 5V regulation are the same 1 One minute after turn if the CPU IC1001 does not detect H and sync IC1001 pin 8 goes LOW Both the heater regulator IC610 not shown and Q606 are turned OFF With Q606 D616 s gate is no longer grounded enabled Pulses from D615 pass through C650 R653 and R664 to the gate of D616 turning this SCR ON When D616 turns ON the 200V line is connected to the 8V line at D621 Cathode C628 on the 8V line charges When the 8V line rises to about 15 6V zener D630 Q608 and IC607 all turn ON This causes the switching power supply input at V Ctrl to be HIGH The prolonged HIGH that is applied to the switching oscillator at V Ctrl first reduces the oscillators ON time in an attempt to lower the output voltage and then finally shuts off the oscillator as it enters the Active Off or Burst Mode In the Active Off Burst Mode the oscillator is turned on in groups appearing as bursts every 0 6 seconds This burst will provide a small amount of power to supply the CPU but not the remainder of the monitor circuits
41. communications through two unused VGA lines between the monitor and the video adapter The DDC2B communication channel is based on the I C protocol The host graphics card can request EDID or VDIF Video Information infor mation over the DDC2B channel Not only is DDC2B faster it allows the operating system to query the monitor for supported features and inform you of any configuration changes For your monitor to be fully Plug and Play compatible it must have both DDC1 and DDC2B capabilities With a Plug and Play video adapter you are able to change resolutions and colors without having to restart your computer Designers are developing innovations to keep pace with Plug and Play such as a communication cable that plugs into a port similar to a tele phone jack on the monitor With the introduction of the ACCESS bus or DDC2AB compatibility include DDC2B bi directional communication and to add connectivity between many devices ACCESS bus peripherals can be daisy chained in any order so that everything plugs into one port on the back of your computer system Since the ACCESS bus conveys information directly to your system mice and keyboards as well as other compatible components can be plugged and unplugged without having to restart your computer Espe cially useful for monitors the ACCESS bus allows you to adjust your screens image using a mouse and keyboard This not only eliminates the need to push buttons on the display it allows y
42. d HIGH OSD RGB output from 003 NoHorV input when BIk is HIGH No Data or Clock H amp V sync data and clock input 1001 CPU V osc output 8 V oscillator data and No Data or Clock out Clock input G2 CONTROL 001 RGB PRE AMP 52001 NPUT SW CUT OFF TO DPU IC801 N BD 11C DATA CLK BUS TO 11C DATA NE DPU IC801 N BD CLK 1001 MEMORY UIC1005 D BD CPU VIDEO BLOCK 38 17 4 1221 1 18 00 Input Input Output Signals This monitor can be connected to two computers A front panel switch selects input 1 or input 2 Each input is identical except for the Plug and Play communications Input 2 only sends unidirectional plug and play monitor information to the computer DDC1 format Input 1 has bi direc tional Plug and Play communications supporting DDC1 DDC2B amp DDC2Bi formats An explanation of Plug and Play can be found in the appendix of this book The signals at the two inputs can be summarized in these charts Input 1 Inputs from RGB video Horizontal Vertical Sync on computer signal Sync Sync Green Outputs Plug and Play DDC1 Unidirectional data or DDC2B computer DDC2Bi Bi directional data If the CPU receives the appropriate DDC commands it will operate in the bi directional mode Otherwise it will assume the DDC1 read only mode when triggered by vertical sync Input 2 Inputs from RGB video H
43. e Burst mode In the Burst mode the power supply will just be able to supply enough energy to feed the standby regulator IC609 The standby voltage keeps the CPU pow ered to keep the monitor latched in this Active Off power mode HV triggered failure is identified when both green and orange LEDs turn on blinking on one second and off the next second This blinking will con tinue until reset by shutting the monitor OFF or unplugging it from AC ABL Detection The automatic brightness limiting circuit normally reduces the High Volt age when the CRT current is excessive Excessive ABL voltage causes CPU 1C1001 to enter the low power Active Off mode for protection An ABL triggered failure is identified when both LEDs are turned on and blink ON for one second and OFF for two seconds Some possible causes are shorted video driver IC004 G2 voltage too high or a picture tube struc tural failure POWER SUPPLY SURGE RELAY RY602 ORG K BURST 200V MODE STBY 1 1001 0 95235 11 DET DET 11C CLK D921 5 6V 01003 5 6V R417 VFBP 3 3V 0405 your IC401 7 SELF DIAGNOSTIC BLOCK 68 HEATER VOLTAGE REMOTE ON OFF RGB OUTPUT RGB PRE AMP 1 002 0912 901 11 3 16V FBT T901 8 0911 R660 R656 200V R661 4 4 1203 1 27 00 APPENDIX Power MOSFET Tests JEIA Transistor Classification Transi
44. e computer or shut off the com puter so there is no sync input the monitor 2 Pressthe monitor switch in A no video input message will appear on the screen when the CRT warms up 3 Move the ball type control button to the left and hold it there for two seconds This must be done before the monitor goes into the Active Off Low Power Mode two minutes after power ON 4 The entire screen will turn white and the power indicator will alter nately blink green and orange This is the aging mode The monitor will exit from the aging mode if The control button is moved to the right and held for two seconds Input sync is detected computer turned on The input switch is changed The power button is pressed again off Image Restoration This circuit is operated by the customer to automatically white balance the picture This is achieved by adjusting the RGB drive signal levels to compensate for reduced cathode emission At the factory the Ik volt ages corresponding to each RGB cathode current are stored into memory When this circuit is activated from the menu the screen turns white for one second as the gain of the R G or and B drive levels are increased When the measured voltages are matched to the ones in memory the operation is complete and the new drive levels are stored The circuit details are in the Video Output text where the Image Restoration circuit resides Lock Control All customer functions can be i
45. e in an Active Off mode When the computer is turned OFF there is no video sync input the monitor Within the moni tor this loss is detected by the CPU not shown The CPU turns ON SCR 0616 which increases the error voltage This increase to 6 5V is detected by 603 14 D608 and the oscillator stops to lower the output voltage Since it takes a longer time for the voltage to return to normal the oscillator resumes in the low output Active Off or Burst mode In the Active Off mode IC603 turns ON the power supply s oscillator in bursts every 163msec 6 times second The bursts last 18 5msec dT4 163ms dV 4 00 Active Power Supply Burst Intervals Name Location Voltage Channel1 Amplified OSC Q605 D 180Vp p Channel2 Oscillator Output IC603 pin 4 11Vp p Time base 50msec div Each burst consists of oscillator pulses at 18 2kHz These pulses change in width to regulate the power supply output voltages in the Active Off mode 23 Active Off Power Supply Burst Location Q605 D IC603 pin 4 200usec div Name Amplified Osc Oscillator Output Voltage 180Vp p Channel 1 Channel 2 Time base These bursts provide sufficient voltage at T602 pin
46. ecking the regulation loop Assuming you have replaced both Q901 and Q902 and there is still a problem with the circuit you can test this regulating circuit without HV by following this procedure First you will disable the HV then use a power supply to simulate regulation in the following steps 1 Disable the HV by shorting Q902 s Gate to Source ground 2 Place a scope probe on IC901 pins 3 and 5 3 Turn the monitor ON without video input and move the front panel control button to the left This will activate the Aging Mode and keep the monitor powered ON In the Aging Mode you should see a 9 6usec positive going pulse at IC901 pin 5 The pin 5 pulse is present when there is input at pin 14 and 1 901 is good Scope set to 2usec time base 59 5 Without HV IC901 pin 3 should be LOW except for a 2msec positive pulse Pin 3 is LOW to try to increase the disabled HV 0 20dvich 1 901 Waveforms disabled Aging Mode Name Location Voltage div Channel 1 H Drive input 901 14 10Vp p Channel 2 PWM Output IC901 pin 10Vp p Channel 3 Output IC901 pin 5 10Vp p Time base 2usec div 6 Through a blocking diode for test equipment safety apply voltage to the cathode of D916 901 11 Watch the waveform at 901 pin 3 As you reach 9V on the external
47. ed for focus at the center of the screen and the G2 voltage is necessary to accelerate the beam after the focus grid slows down the electrons Video Processing The video processing block consists of an input switch amplifier and out put stage An on screen display 1 003 is added to provide visual feed back about the monitor functions and features e TXD Transmits signal to DAS computer RXD Receives signal from the DAS computer Stby 5 Monitors power Present when the monitor is ON Gnd Common ground A computer loaded with DAS software permits monitor adjustments by changing the data stored in memory 1 005 not shown via CPU IC1001 The DAS software will permit the technician to change this memory data which affects these stages DAS Control via CPU 1001 Adjustment Circuits used CRT background and G2 level 001 amp V Position centering 001 Video signal positioning H amp V Size IC801 Deflection size Pincushion C801 Pin Output transistors C801 Conv Outputs Convergence 1 003 050 11 DATA CLK STBY 45V IC1001 POWER REMOTE SUPPLY ON OFF V F SYNCO OVERALL BLOCK G2 CONTROL RGB IC002 RGB OUT 901 Q902 HV PROTECT OUTPUT H V DF Q501 Q503 H DRIVE PROTECT 1 2 1001 H D YOKE VSAWIN PROTECT 3 1 1001 16 04 1220 1 19 00 Power Saving Modes This monitor has four power modes The CPU m
48. ed in memory 1005 not shown is CN1005 pin5 1 69 OVp p 1Vp p Complex changed during convergence using DAS software During this alignment ONTO DnE OV V on screen grid is displayed A cursor identifies a point on the grid to be pin compex converged At that point each color can be moved to converge all three CN1005 pin7 1 61 0 5 2Vp p complex colors producing a white grid The cursor is then moved to the next All voltages and wave shapes taken in the Aging Mode alignment location VFBP V OUT 4012 7 DB IC801 HFBP DPU Q507 E CXD9517Q D BD IC1001 gt 36 37 ee 25 18 CN1005 CN701 CN11 1 701 LA6510 EE CONVERGENCE YOKES 15V DIGITAL CONVERGENCE CIRCUIT 10MONO4 1219 1 14 2000 66 67 Self Diagnostic Function The front panel combination green orange LED is used to indicate the following e Loss of input sync see Power Saving Modes e Failure in the High Voltage and Vertical Output Stages e Excessive ABL current picture tube or drive failure The following chart shows the LED indications and what level of voltage at CPU IC1001 will activate enter this protection mode Once the trip voltage is exceeded the CPU enters the Active Off power mode and remains latched in this state until you press the power button to reset the CPU Self Diagnostic Indication Function Indication Defective St
49. een The white screen aging signal leaves as pulses from the RGB outputs at ICOO3 pins 14 16 They are accompanied by blanking signal of the same polarity at ICOO3 pin Aging Signal Output Name Location Wave Shape OSD Aging signal ICOOS pin 14 16 bright ICOOS pin 17 qr switching unblanking The RGB Preamp 1 001 serves as an RGB preamp and a switch The blanking signal goes HIGH to disable the RGB signal and enable the OSD signal from IC001 pins 13 15 CRT Bias Even though there may be signal at the RGB cathodes the signal will appear very dark unless the CRT is biased properly 1 001 and 1 004 set the cathode and G2 bias voltages for the CRT At power ON pertinate data stored in memory 005 not shown is selected by the CPU and sent to RGB Preamp 1 001 R OUT FROM 1 008 27 30 355 G OUT RGB OUT LM24026 B OUT B 11C FROM 1 1001 36 37 SDA D BD SCL CONT 3 H8D2972 7 0108 128 R108 A 01 tk Li 25V L L REDIkI Gik R115270k FILT FILTER V SYNC IC1001 26 H SYNC 1 1001 27 gt BUFF Q507 E VIDEO OUTPUT 8 04 1210 1 19 00 42 Part of IC001 serves as a D A converter The data from CPU IC1001 pin 26 is input 1 001 to make the analog background cathode bias voltages and the G2 voltage DC background voltages leaving 001 30 32 will correspond directly to the CRT cut off v
50. eginning of any data transfer is a start bit The start bit has clock pulse Any time the data lines falls from HIGH to LOW independent on the clock line usually HIGH all devices on the bus will begin loading in the data on the bus The stop bit is conversely a LOW to HIGH transi tion from the master IC Slave Address The address word consists of a seven bits of an eight bit word Current technology digital communication is often in 8 16 or 18 bit words This address identifies the device that this data is for Read Write Bit The eighth bit of the address word is the direction read write bit It is HIGH to accept the pending data for reading and LOW for WRITE into the addressed IC Acknowledge Bit Following the address from the master IC is an acknowledgement from the destination IC At this time the master IC s tri state data output will switch to a high impedance input As the pull up resistors on the data line bring this line HIGH the destination IC grounds this line at this time in the clock cycle to indicate an acknowledgement of the address or data and verify the presence of the destination IC Plug and Play VGA VESA DDC VGA Video Graphics Adapter or Video Graphics Array VESA Video Electronics Standards Association DDC Display Data Channel 00000 C At the monitor cable 15 PIN HIGHDENSITY D SUB FEMALE at the video card 15 PIN HIGHDENSITY D SUB MALE at the monitor cable
51. emory 1005 1 1701 manu factures the static and dynamic convergence signals All of the memory data is transferred to the CPU at power ON The CPU then sends the data to pertinent ICs The convergence data is sent to IC801 The static convergence signals created by 10801 affect the center of the picture The two convergence signals XSC and YSC are amplified by 1 701 and applied to convergence coils that affect the beams in the X and Y axis respectively The dynamic convergence signals are also made by 1 801 but they af Convergence Output Signals fect the convergence along the perimeter of the screen These complex Scope Name Location Voltage div convergence and 2 Channel 2 Static Conv Yoke 3 1 701 9 0 5Vp p Static Convergence Signals from DPU 10801 Channel 3 Dynamic Conv Yoke 2 702 6 2Vp p Location DC AC Vert AC Horiz Wave Shape Channel 4 Dynamic Conv Yoke 1 IC702 pin 1 2 5Vp p CN1005 pin 2 1 57V 0 2Vp p 0 8Vp p Time base 2msec div CN1005 pin 1 43 OVp p 1Vp p All voltages and wave shapes taken in the Aging Mode CN1005 pin 4 1 65 0 2Vp p 0 8Vp p Dynamic Convergence Signals from DPU IC801 Alignment Location DC AC Vert AC Horiz Wave Shape The Digital Convergence data stor
52. enerator under Adjustments You should find a pincushion waveform from the DPU in all modes but at different frequencies at CN1005 pin 14 In the aging mode the waveform is 0 4 1 8Vdc The waveshape is a parabola Capacitors are switched into the horizontal output circuit by Q511 Q516 for linearity and width correction The caps and MOSFET devices can be removed from the circuit and checked See the section under MOSFET Testing in this book Protection Circuitry A loss of main horizontal drive to the yoke will cause a vertical line to be burned into the middle of the CRT within one second Q507 monitors the horizontal drive pulses and feeds a representative DC voltage back to the CPU to protection the monitor Q507 Voltages Normal Operation Wave Shape Location Emitter Q507 also feeds this horizontal pulse to two other locations e OSD 1 003 7 to provide OSD character positioning DPU 1 801 29 to reset the geometry signals generated 0511 0516 CPU gt 1 1001 46 50 CPU gt 1001 4 5 0 1 1001 27 1 1001 SW CIRCUIT DC Q506 200 gt MM PIN OUT R511 0 47 5 CN802 1 501 0508 9 14 PWM CONT Q501 Q503 H DRIVE C503 0 01 CN801 CN1006 HORIZONTAL OUTPUT 56 HFBP TO 1 OSD 003 7 D BD 2 CPU 1 1001 32 3 DPU IC801 29 N BD Q505 H OUT 2805445 N 12 0 04 1209 1 19 00
53. ent CPU is functioning in the Normal Power Mode but the power supply is in the Active Off Mode Test D616 short and Q606 open or pull D616 out of circuit to see if the Normal mode is possible Measure D621 C voltage 8V is normal Higher voltages means Q609 or D616 is shorted Lower voltage means D630 is shorted Even without the video cable connected the monitor stays in the Normal Mode does not go into the Active Off Mode There could be noise detected by the CPU and mistaken for sync The Active Off trigger circuit is not responding If the Orange LED lights after one minute the CPU senses no sync and it is responding normally The problem is in the Active Off trigger circuitry about Q606 D616 and D617 Repeated Stby 5V 1 609 regulator failure Input measures 40V instead of 12V in the Active Off Mode Standby regulator input voltage is not being regulated Q609 and D630 are suspect Original IC609 was open A replacement IC609 gets hot before failing 603 0605 SWITCHING POWER SUPPLY OP ISOLATE TLP621D4 MAIN ERROR REGULATOR CIRCUIT 200V SOURCE 0615 2W 667 47k2 Res 9606 HEATER FROM 1 1001 8 STBY 45V 2 5V R682 R676 608 SHUNT REG TL1431 VOLTAGES 681 C644 WERE 0 05 MEASURED IN THE NORMAL POWER MODE
54. ere are several parts between the AC input and the bridge rectifier D625 The function of these parts are explained in the chart below AC Input Parts Part Name Function Possible Symptoms if defective F601 Input fuse Current limit Monitor is dead R674 Resistor Bleeder Arcing at plug when unplugged from AC LF602 Choke Line noise Intermittent noise on monitor canceling screen and or radio TV VA601 VDR 375pf Clips incoming voltage spikes interference Monitor is dead Intermittent failure of monitor s power handling parts Shorted Open fuse C636 amp C637 Reduces the Constant radio TV interference Capacitors amplitude of Repetitive VDR failure incoming outgo ing noise spikes TH600 Limits the Open Dead set Thermistor monitor s turn Shorted D625 failure 6 5 ohms cold ON surge current 5601 ON Off Passes AC to Unreliable power Switch monitor VDR VA601 Operation The resistance of a VDR will drop from infinity to a low value depending upon the construction when the voltage applied to its terminals exceeds the trigger voltage This reduction in resistance will reduce a high volt age but low energy pulse width voltage spike and prevent it from punc 17 turing damaging semiconductors in the monitor The VDR returns to infinite resistance when the applied voltage disappears VDRs will not shunt a high energy pulse from a direct lightning hit
55. ers the standby mode when there is no input signal de tected The monitor shuts down and the graphic disappears into a dark screen The front panel indicator LED changes from green to orange 3 Activating any front panel user function will return the monitor to the ON mode where the graphic will reappear The front panel functions are e Input switch input 1 or 2 e Menu control Any direction up in outward left right Reset button m Note During testing you may return from the Active Off Mode without an input by pressing any front panel button As the monitor powers up it is normal for the power supply s oscillator to run at one of two frequencies The oscillator may run at the lower oscillator frequency of 21kHz instead of the full power mode of 65kHz It will sense an increase in load and switch automatically when necessary Power OFF Initial conditions Unit is in standby mode No video input 1 Press the power OFF button 2 The orange LED goes dark after three seconds Aging Mode This mode is commonly found in Sony monitors and warms up the in preparation for the technician to perform color temperature adjustments By pressing a series of front panel buttons different for each model this mode can be activated The CPU detects this button combination and places a DC bias on the CRT cathodes to produce a white screen The procedure in the CPD G400 is as follows 1 Disconnect the video cable from th
56. fault levels except The menu language The menu position The Control Lock function if it was ON The reset button does not work when the lock is ON Reset Just One User Adjustment Entering the menu setting you wish to reset with the control button and pressing the RESET button does this Self Diagnostic Function The front panel orange green LED is used to determine what section caused the monitor to enter the protection state This is explained in the Self Diagnostic Function section of this book Overall Block The overall block diagram shows the major sections of the Sony model CPD G400 monitor that house a F99 chassis The following blocks are listed by operational importance Power Supply Deflection e High Voltage e Video Processing Power Supply The power supply block consists of the voltage generating and regulating power supply and the managing CPU IC 1001 The power supply delivers standby 5V to the CPU to keep it alive In turn CPU 1 1001 uses two outputs to select the power supply s operating modes The mode de cided by the CPU is based upon the input sync and protection circuit Protect 1 3 signals CPU Power Supply Control Lines Modes used Active Off no H amp V sync input Protection latched in the Active Off Mode Purpose Shuts off Output Heater CRT filaments and enters Active Off low power burst Mode Switches the 5 and 12V OFF Remote Standby n
57. gaussing is characterized by a strong humming noise at power on that only lasts approximately one second During this second the picture tube is engulfed with a strong AC field and the AC current consumption is about 6 AC amps If the magnet is external to the monitor the undesired color will return Remove the external magnet 0608 DIGITAL TRANSISTOR DEGAUSS PWM2 1 001 5 ON OFF 5601 R604 158V TO IC603 1 SRT T602 9 R605 C611 2 7 OHMS L 470 SURGE PROT 1MON4 1196 1 19 00 DEGAUSSING SURGE PROTECTION 18 Circuit Operation Degassing only occurs after the front panel power is pressed The se quence of operation is as follows 1 Press the power ON button not shown 2 158V is applied to the power supply stage not shown 3 The power supply stage makes standby 5V for the CPU IC1001 and reset 1 1003 not shown Once the CPU is reset IC1001 pin 5 outputs a HIGH to activate the degaussing circuit The CPU HIGH turns on relay driver digital transistor Q608 has inter nal resistors to operate with 5V input Q608 grounds degaussing relay RY601 energizing it RY601 s contacts close passing 120VAC through TH601 to the de gaussing coil around the bell of the picture tube The AC demagne tizes the internal metal parts of the picture tube Within two seconds TH601 has increased resistance from 4 2 ohms cold to a few 100k ohms hot In approximately six seconds after the power
58. have switched over to a communications bus that has more advantages than disadvantages The major advantages are e Oneless communications line no latch strobe enable acknowledge or chip select line As part of the CPU program the number of slave IC on the bus is reconfirmed each time at start up after CPU reset Bi directional data is commonplace but unidirectional is possible for drivers e Eliminates the need for two communications buses in complicated products Communications data and clock are always present as long as the set is ON active e More than one master IC can be programmed into the fixed number of ICs on the bus so one IC does not have to talk to the master to com municate with another IC Using this communications format only parallel data and clock lines connect the ICs Instead of singling out a slave IC using individual chip select lines to communicate on the bus the specific device is addressed within the data This format makes monitor adjustments possible from an external device using DAS software The connection to the 11 bus via a connector on the board is usually near the CPU Data Format The IIC bus has several parts e Start Bit e Slave Address Read Write Bit Several Acknowledge Bits The Data Stop Bit Start Slave Read H Ack Data Ack bit Address Write L Start Stop Bit Each device on the IIC bus must be able to recognize its own address The b
59. ias Memory 1 1005 stores the CRT bias parameters They are loaded into the CPU when the CPU is reset at the time the power switch is pressed G2 and cathode DC threshold background cutoff voltage data are sent along the bus into RGB Preamp 001 1 001 translates the data into analog voltages to make G2 and background voltages for the CRT Addi tional G2 and background driver ICs are needed to make the high volt 37 ages necessary Adjustments to this data are made using an external computer using DAS software Troubleshooting Dark screen Even if RGB video is input the monitor the signal can be inhibited at several ICs along the path RGB Signal Inhibited causing a Dark Screen Check for Slide front panel input switch to correct position Blockage Location 1 008 Input Switch Reason for blockage Input not selected 1 001 RGB CPU detects no input BIk signal from 1 003 Preamp sync LOW Normal HIGH No IIC data input OSD blk interval 1 003 Data Clk from CPU to 003 Blanking OSD 003 output line held HIGH H amp V sync input CPU Check for 80 from LV power supply G2 voltage from FBT 1 004 in and out voltages 1 001 Bkg output voltages IC002 RGB Output 80V B missing CRT No G2 voltage Cutoff voltage set too high No Menu Messages No OSD or White Screen in the Aging Mode Location Reason Check for 1 003 OSD output hel
60. in the pincushion stage 501 Q506 Q508 0509 This signal is also known as west because it is used to correct the inability of tordial yokes to provide extra deflection at the middle of the picture This is why early picture tubes were round East and west were used to designate the black areas at the left and right sides of the screen that required correction Extra sweep current from the pincushion stage is applied to the yoke to elimi nate the black areas Insufficient scan black black Pincushion Distortion Vertical Deflection The V Saw In signal from the DPU 1 801 is used in the Vertical Output stage This stage sweeps the CRT electron beam from top to bottom The oscillator in the CPU IC10101 controls the speed The DPU IC801 controls the vertical size and linearity by shaping the sawtooth signal that is output 401 has its own internal voltage generator to make extra voltage required during vertical retrace when the output voltage is double the main ramp voltage A failure in this internal voltage generator will cause no deflection or poor linearity A line will be burned into the CRT within a second during a vertical or horizontal deflection failure For pro tection from a CRT line burn the internal voltage generator pulse repre sents vertical output operation The CPU monitors this signal and latches the monitor into the low power when there is a loss of the protect signal
61. les the 200 V B from T602 for voltage regulation in all power modes except Active Off The regulator operates differently in e The Normal Standby Suspended modes and e The Active Off Burst Power Mode 31 Regulator Operation Normal Mode Regulation is performed by predominately 608 in the normal standby and suspended power modes The voltage from a secondary winding of T602 at D621 is used for regulation This sample voltage is reduced by resistor string R676 R681 and R682 then applied to 1 608 1 608 TL1431 is a error regulator IC designed to shunt lower its output volt age to ground until its input voltage returns to 2 5V Capacitors C642 C641 and resistor R679 are used to slow the response time of shunt regulator 1 608 and prevent oscillation The output voltage from shunt regulator IC608 pin 3 is input to optical isolator 607 2 607 not only inverts the signal but also provides electrical isolation between the input and output signal Finally IC607 s output at pin 5 is applied to the switching power supply to adjust the pulse width of the oscillator signal for secondary voltage correction If the output of transformer T602 increases the final correction voltage fed back to the power supply oscillator at V Ctrl will also increase This is shown in the chart below In the power supply as the V Ctrl voltage increases the oscillator conduction time decreases This decrease low ers the energy fro
62. lses White screen Each cathode s signal is rectified and the corresponding DC voltage is applied to ICOOS pins 20 22 Drive Level Balancing During the measurement mode 003 translates the Ik analog volt ages that represent a white screen and sends them to CPU IC1001 one color at a time The original Ik voltages were stored as data in memory when the monitor was new The CPU compares the old and new Ik data If they do not match data is output the CPU into 001 001 increases the R G or B gain that correspondingly increases the Ik voltage from 1 004 003 sends new Ik data to CPU 1001 for a second compari son The process repeats until the new and old Ik voltages in IC1001 match The gain level is stored into memory and used every time the monitor is turned on The procedure is then repeated for the other colors At the conclusion of image restoration the CPU 1 1001 sends 1 003 data to discontinue the white screen and disregard the Ik voltages input pins 20 22 Summary of Video IC Operations amp Voltages IC Used In Modes Function RGB Preamp Normal Display RGB Preamplifier 1 001 OSD Menu RGB OSD switch Aging Background Voltage D A Conv Ik image restore G2 Voltage D A Conv RGB Output voltage amplifier Output 002 Same as above 45 OSD OSD Menu Makes menu graphics and a 003 Aging white screen Ik image restore Performs image restore calculations Horiz
63. m T602 s secondary windings returning the voltage to normal Regulation Correction Path Normal Mode Power Supply Shunt Reg Shunt Reg Opto Isolator Output Input Output Output D621 C IC608 pin 1 IC608 pin 3 IC607 pin 5 Increases 1 Increases 1 Decreases Increases 1 Regulator Defect Open Circuit An open circuit in this regulation loop will cause OV at V Ctrl The switch ing power supply will then generate excessive voltage The larger feed back voltage from T602 into the switching power supply DEM will shut off the power supply momentarily This occurs when the 200 line reaches about 220V When the voltage drops to about 180V the oscil lator will start again only to be shut off when it reaches 220 The result ant power supply and front panel green LED will start and stop in unison at about 2 Hz 603 0605 SWITCHING POWER SUPPLY OP ISOLATE TLP621D4 MAIN ERROR REGULATOR CIRCUIT 200V SOURCE 0615 2W 667 47k2 Res 9606 HEATER FROM 1 1001 8 STBY 45V 2 5V R682 R676 608 SHUNT REG TL1431 VOLTAGES 681 C644 WERE 0 05 MEASURED IN THE NORMAL POWER MODE 1 L V REGULATOR CIRCUIT 6 04 1202 1 24 00 32 Regulator Operation Active Mode In the active off mode only the standby 5V is operational Q609 IC607
64. nhibited from the Option menu except the front panel Input and Power switches This is used to prevent children from resetting all your monitor settings S RGB This is a preset industry standard color setting used with information from the internet and with a SRGB compliant printer When a sRGB standard color object is indicated on the internet you may view it in that true color by selecting SRGB from the menu s color group If you have a sRGB printer you may print the object at that color too The sRGB setting just fixes the brightness and color levels to pre estab lished settings Customer Convergence The customer can move the red and blue centering adjustments from the menu This can be done in the horizontal and vertical plane Moir Adjustment When fine lines are viewed though other fine lines additional patterns are developed when the lines do not coincide For example if you were look ing at a window blind through a box fan with a grill some lines would not be visible and others would appear distorted This is the Moir effect In a monitor it corresponds to picture lines presented on a vertical slotted CRT internal aperture grill The Moir adjustment affects high frequency video response Reset All User Adjustments You can reset all user adjustments by pressing and holding the front panel RESET button in for two seconds when there is NO menu displayed on the screen All menu customer settings are then reset to de
65. o H sync input Suspended V sync input e Active OFF no amp V sync input e Protection latched in the Active Off Mode Deflection The deflection block consists mainly of the oscillator the vertical and the horizontal deflection stages These stages generate the signal required to make the magnetic field in order to move the electron beams across the screen Main Deflection Blocks Stage Parts Function Oscillator 1001 e Make horizontal and vertical signals at a default frequency e Matches its oscillator frequency to the computers sync signal when input Vertical 801 Shape the oscillator pulse into Deflection IC401 ramp waveform Vert D Yoke Amplify the vertical ramp to drive the yoke coil Horizontal 801 e Shapes the oscillator signal into Deflection 0501 0504 the correct width Amplifies the signal to drive the horizontal yoke coil Stages that support Vertical and Horizontal Deflection are the dynamic focus pincushion and convergence stages These stages ensure that the beam is uniformly focused fills the entire screen and that all three beams land at the right place on the screen 1 003 050 11 DATA CLK STBY 45V IC1001 POWER REMOTE SUPPLY ON OFF V F SYNCO OVERALL BLOCK G2 CONTROL RGB IC002 RGB OUT 901 Q902 HV PROTECT OUTPUT H V DF Q501 Q503 H DRIVE PROTECT 1 2 1001 H D YO
66. of about 400 to 1k ohms This D S resistance will increase toward infinity as the gate charge dissipates leaks off the gate The speed of the gate charge dissipation varies depending upon The power MOSFET number internal construction l and e The charge voltage from your ohmmeter For example the power supply stage 2SK3265 MOSFET device will show increasing drain to source resistance values on a Fluke model 8050 digital meter 2k ohm diode test range for less than two seconds before over ranging Other power MOSFETs may hold their gate charges longer and their cor responding D S resistance will very slowly increase taking minutes or days to over range Touching the source and gate with your fingers will dissipate the gate charge and cause the D S resistance to increase rap idly The P channel power MOSFET can be tested in the same manner but you must reverse the ohmmeter leads e g connect the positive ohmme ter lead to the MOSFET s SOURCE terminal Prevent MOSFET Damage To prevent damaging the power MOSFET Do not apply more than 20 volts to the gate terminal with respect to the source Prevent static electricity from touching the MOSFET Do not forward bias the internal drain source zener diode with a power supply D ril N Channel MOSFET w internal zener or Bus Overview In recent years Sony monitors television and other Sony and non Sony consumer products
67. oltages 1 004 amplifies the analog background voltages from 001 and applies them to the three diodes Diodes D106 D206 D306 and associated pull up resistors e g R109 R122 establish the cut off voltage threshold for the CRT cathodes at about 110V in this monitor The RGB signal capacitor coupled to the cathodes reduces the DC cutoff voltage to brighten the screen with infor mation lettering Sample Background Control Voltages Aging Mode DC Voltage 5V data and clock is present all the time except when the unit is Off or in the Active Off Mode 3 8V 4 7 7 111 Location 1 001 4 001 30 32 1 004 15 14 amp 13 004 3 5 amp 7 CRT cathodes RGB The Aging Mode is set by unplugging the monitor s video input turning the monitor ON and holding the control button to the left The screen will be all white while the front panel LEDs blink green orange RGB Preamp 1 001 also serves to make the G2 voltage Data from the CPU 1 1001 is translated into a DC voltage to represent the G2 voltage that leaves 001 29 This voltage is directly proportional to the final G2 voltage applied to the CRT G2 grid On Screen Message Display OSD 1C003 generates the monitor s on screen display graphics and the white screens used in the imager restoration and aging modes When the CPU 1001 not shown detects a front panel control bu
68. on the power line Hopefully the VDR will short and take out the fuse saving other parts within the monitor VDR Testing 1 Measure the resistance across the VDR terminals A good one will read infinity open 2 To ensure the VDR is not open internally measure its capacitance The capacitance will vary depending upon the construction and ven dor but none should be open no capacity unless bad The trigger voltage is usually related to the part number that is stamped on the VDR In this unit VA601 is stamped 471K 470 Volts and measures 375pf out of the circuit For comparison a different vendor VDR taken from a TV is stamped 430NR and measures 198pf 3 Having a capacitance only proves the VDR is not open It does not prove that it will operate at the trigger voltage When the monitors power handling parts periodically fail without cause the VDR is in doubt Replace it Degaussing Circuit Purpose Color TV sets and color monitors have electron beams that are targeted to a specific location on the screen An external magnetic field can move the beam to an undesired location on the screen changing the desired color near the source of the magnetism This can occur when a part of the picture tube s metal structure is magnetized in transportation or by placing an unshielded speaker magnet nearby Applying a strong AC field about the tube at turn ON can demagnetize the tube This picture tube demagnetizing is called degaussing De
69. onitor is first turned ON a large capacity 470 mfd C095 charges slowly keeping the base of 0006 initially LOW This turns 0006 which slightly re duces the control voltage at 1 005 5 This voltage is applied to buffer 0001 producing alower G2 voltage The slightly lower G2 voltage keeps the picture dimmer at turn ON 47 When the monitor is turned ON from a cold start the CRT filaments take a while to stabilize As a result the picture is not as bright as when they reach normal operating temperature and the monitor has stabilized The G2 start circuit using Q6 increases the picture brightness slightly at power ON and then very gradually shuts itself OFF When the monitor is first turned ON a large capacity 470 mfd C095 charges slowly keeping the base of 0006 initially LOW This turns ON Q006 which reduces the control voltage at 1 005 5 The LOW control volt age is applied to 1 005 producing a slightly lower G2 voltage The lower G2 voltage keeps the picture brighter at turn ON In about a half hour after turn ON C095 charges enough to turn 0006 OFF so 0006 is electrically removed from the G2 circuit By then the CRT brightness has reached normal Circuit Voltages Normal Operating Voltages at turn ON Name Location Voltage G2 Control 1 001 29 2 38V Inverter input 1 005 5 2 74 Inverter reference 1 005 6 2 88V Inverter Output IC005 pin 7 8 46V Buffer reference
70. onitors video input sync to select the monitors power mode of operation Normal Operation When CPU 1C1001 pins 20 and 30 detects both vertical and horizontal sync or Sync On Green is detected at IC1001 pin 28 the power supply operates normally and the monitor is unblanked The front panel combi nation orange green LED only lights green Standby Power Mode When there is only a loss of horizontal sync at IC1001 pin 30 the monitor shuts down some of its circuitry CPU IC1000 pin 7 goes LOW shutting off the 5V supply line to the monitor At the same time IC1001 pin 52 causes the orange LED to blink continuously while the green LED re mains ON Suspended Power Mode When Vertical sync is lost at IC1001 pin 20 the monitor shuts down some of its circuitry CPU IC1001 pin 7 goes LOW shutting off the 5V supply line to the monitor just as above Atthe same time IC1001 pin 52 causes the orange LED to also turn ON Both LED on means the monitor is in the Suspended Power Mode Active OFF Power Mode A loss of both horizontal and vertical sync causes the monitor to enter a very low power consumption mode The CPU responds to no sync by placing the outputs at IC1001 pins 7 and 8 LOW The LOW from pin 7 shuts off the 5 and 12 volt supply lines to the monitor causing blanking as in the previous standby and suspended modes When 1001 8 goes LOW the power supply enters the burst mode of operation In this mode the power supply is
71. orizontal Vertical Sync on computer signal Sync Sync Green Outputs to Plug and Play DDC1 Unidirectional data from the computer monitor DDC1 data is only output when Vertical Sync is received Signal Levels For signal tracing the signal levels in this stage are shown in the charts for each 1 008 and 1 009 are used to select one of two RGB and sync inputs the monitor will use The S2001 input switch is located under the bezel and its voltage is applied to both ICs 1 007 contains Plug and Play information about the monitor s resolution and sync speeds This information is sent to the computer so the com puter will only choose a sync speed the monitor can support no loss of sync when entering a software program 39 Input Select Switch 008 Name Input Output Location Level Location Level RGB input 1 Pins 2 5 7 1Vp p Pins 27 1Vp p RGB input2 Pins 11 13 16 1Vp p 30 35 Input Sw Pin 19 Low input 1 High input 2 Sync Switch 009 Name Input Location Level Location Horiz amp Vert Pins 5 12 4p p Pins 5 14 Sync input 1 Horiz amp Vert Pins 3 13 4 Sync input 2 Sync on Green Pin 2 4p p Pin 15 4 Input 1 Sync on Green Pin 1 4 Input 2 Input Sw Pins 7 10 Low input 1 11 High input 2 DDC1 1 007 Name Location Signal Level Comments V Clock Pin 7 4p p In
72. ou to store monitor settings under meaningful names that are easily recalled The newest standard USB Universal Serial Bus includes all the capa bilities of ACCESS bus but transmits and receives data at a much faster rate Instead of 400K sec USB will be able to communicate at an incred ibly fast 12MB of data per second which makes it ideal for digital video and telephony Because of its transmission capabilities USB is expected to win over the current ACCESS bus standard and will be the one to watch as Plug and Play continues to mature DDC Data Format EDID Basic EDID consist of 128 bytes Number Description 8 Bytes Header 10 Bytes Vendor Product Identification 2 Bytes EDID Version Revision 5 Bytes Basic Display Parameters Features 10 Bytes Color Characteristics 3 Bytes Established Timings 16 Bytes Standard Timings 72 Bytes Detailed Timing Description 1 Byte Extension Fla 1 Byte Checksum Monitor Problems Checklist While involved with testing in one circuit a related circuit can be over looked For each 12 symptoms listed in the chart below there are corre sponding items that need to be checked They are described in the text that follows Summary of Symptoms Green power light ON but 2 Very dark picture 8 Intermittent Cut Off Control IC 3 Very dark picture and 9 Can only focus in the center or at 7 Retrace lines present in the no picture screen
73. out current limiting thermistor TH600 so the monitor will have full power Operating Voltages and Resistances Circuit Voltages At Power ON 4 9V OV After 2 seconds OV 11 8V Location 1001 5 Q608 Collector D628 Anode D627 Cathode Q607 base 2 3V OV OV 11 8V 8 6V 0 72V Q607 Collector R672 RY602 OV OV OV 2 92V Selected Part Values Function Measured Resistance 6 5 ohms cold Surge Resistor 4 2 ohms cold 15 6 ohms Degauss Thermistor DGC Coil Degaussing 0608 DIGITAL TRANSISTOR DEGAUSS PWM2 1 001 5 ON OFF 5601 R604 158V TO IC603 1 SRT T602 9 R605 C611 2 7 OHMS L 470 SURGE PROT 1MON4 1196 1 19 00 DEGAUSSING SURGE PROTECTION 20 21 Switching Oscillator This switching oscillator stage generates seven voltages for the monitor to operate normally The stage consist of three major parts Switching Regulator IC603 Contains an oscillator that runs at 26kHz or at bursts of 18kHz Duty cycle regulation Power Handling Q605 A MOSFET can control the high current at the wide operating frequency of the oscillator Sine Resonate Transformer T602 Produces the various voltages required by the monitor This monitor s power supply has three operating modes One mode is selected depending upon the amount of load When the load has changed measuring the current needed to res
74. output at pins 20 23 and 27 respectively 1 001 also serves to switch to the OSD signal input pins 13 15 and use serial data input pins 3 4 to control the G2 voltage from pin 29 The 4Vp p RGB output IC001 pins 20 23 and 27 are sent to second amp 002 The sole function of this IC is to increase the 4Vp p input to about 56 output at pins 1 3 and 5 using 80 from the low voltage supply 002 is protected from CRT voltage spikes due to internal arcing by diodes D104 and D105 Similar diodes protect the G amp B outputs at IC002 pins 1 and 2 but they are not shown for simplicity The 56Vp p RGB signal is capacitor coupled to the CRT cathodes 41 RGB Signal Path Signal input from computer Location DC AC Wave Shape 1 001 10 12 1 9V 1Vp p 002 8 9 8 11 2 8 4 002 1 amp 5 43V 56Vp p J Aging Signal The aging mode is used to warm up the monitor prior to adjustments In this warm up mode the screen is bright and the front panel LED alter nates between green and orange The Aging Mode is entered when there is no computer signal input to the monitor and the control button is moved to the left and held for two seconds When the CPU detects no sync input and the control button was held left the Active Off Mode is suspended and the Aging Mode begins CPU 1 1001 sends data and clock to the instruct OSD IC003 pins and 4 to generate a white scr
75. put sync DDC Data Pin 5 4 5Vp p Output when V clock is input DDC Clk Only input when timing is needed 1 15 DDC DATA CLK TO CPU 1001 34 35 SW IN 52001 gt CN1002 CN309 RGB TO 1 008 11 13 16 R054 10k INPUT 2 DDC DATA CLK C064 INPUT SELECT M52758FP INPUTJACK No 2 INPUT SEL c2 TO 1 008 19 1 T 0004 SYNC SW BU4053B v2 Q3 VCLK C130 OUT 1Vp p TO RGB PRE AMP 1 001 10 13 H gt OUT C230 BOUT C330 0 22 STBY 45V TO INVERTER 1 006 1 11 V OUT H OUT G OUT TO SYNC SEP CIRCUIT Q002 B H2 3 A BD 8 5 1C007 7 STBY 5V INPUT 40 7MONO4 1208 1 19 00 Video Output Overview The video output stage consists of several ICs that Amplify the computer RGB signal and Provide CRT bias to display the RGB signal Two features result in additional usage of ICs in this video output stage An onscreen messages CPU IC1001 OSD 003 and RGB Preamp 1 001 Image Restoration CPU IC1001 Cutoff Control IC004 OSD 1 003 and RGB Preamp 1 001 RGB Amplification RGB Signal The RGB signal from the computer is amplified by two ICs before being capacitor coupled to the three cathodes of the CRT RGB Preamp 1 001 pins10 12 receives the computer RGB signal selected from inputs 1 or 2 001 amplifies the 1Vp p signal input to 4Vp p
76. r at the flyback transformer if the flyback is used for the filament power 4 Symptom A color is too weak bright The problem area can be in the DC bias voltage applied to the CRT cath odes or in the RGB drive signal that is AC coupled to the CRT cathodes We will stop the drive to see if we can get equal DC bias voltages at the RGB cathodes to produce a white screen Procedure Place the monitor into the aging mode or just feed in a dark screen input just sync Increase the brightness and turn down the con trast picture drive level Increasing brightness just uses the cutoff con trol IC to bias the RGB CRT cathodes with a DC voltage These cathode pins should now be at the same voltage Problem Area RGB Cathode Monitor Screen Voltages at the CRT White Color dominant All the same RGB drive output CRT is bad problem One is different One CRT cathode RGB Out Off IC its is weak peripheral parts or RGB background memory data is defective corrupt Symptom One or colors flicker intermittently Inspect the video cable for bent pins cuts and stains liquid damage Often the solder connections break loose at the video input jack where it meets the circuit board Resolder all the connections c Tap the circuit board with an insulated tool like a pencil eraser The closer you get to the bad solder connection the more often the prob lem will appear Resolder the area 6
77. rcuit Although the switching power supply oscillator runs while there is voltage at Vaux IC603 pin 6 the power supply stage will not maintain the correct output voltage without the following e T602 Feedback DEM into IC603 pin 13 for low or over voltage pro tection The Regulator Circuit from D621 to V Ctrl IC603 pin 9 for voltage stability T602 Feedback The DEM p p feedback fdbk voltage from the Sine Resonate Trans former SRT T602 is used in the Normal Power Mode for protection A peak voltage above or below limits will change the oscillator to lower T602 s output voltage for safety Low Voltage A severe short at a T602 secondary will drastically lower the DEM feed back voltage For example if this DEM feedback voltage were removed or shorted at IC603 pin 13 the following output voltages would reduce to these new levels 200 gt 145V 80 gt 56 8V gt 6V High Voltage If the 200 output voltage rose to 220V the oscillator would be momen tarily inhibited The oscillator would start and stop causing the CPU volt age and green LED to also start and stop The Regulator Circuit The regulator circuit has three major parts 607 Optical Isolator IC transfers correction voltage from the cold ground side to the oscillator s hot ground side Q609 Used to regulate the oscillator during the Active Off Burst Mode so the standby regulator IC609 can produce standby 5V IC608 Samp
78. servicing NO High Voltage Testing Position This position allows you to troubleshoot almost all the stages of this moni tor except the HV stages and the sections that are fed voltage from the flyback secondary These sections can be tested with an ohmmeter or by repositioning the chassis for the full voltage testing Sections Tested without HV Full Power Testing Partial Testing L V Power Supply Vertical Dynamic Focus Video Processing G2 Control section Vertical Output Horizontal Output Pincushion Horiz Dynamic Focus Convergence CPU amp DPU No Power Testing High Voltage stage General Procedure 1 2 omn viii Remove shielding to expose the area you need to test Leave the Degaussing coil convergence yoke rotation coil and HV anode lead unplugged Reconnect the main yoke to prevent the protection circuit from acti vating Disable the HV from the top or bottom of the board by shorting the HV Output transistor s Gate to Source leads Plug the monitor into AC Move the control button to the left and hold it there for two seconds while the monitor enters the Aging Mode This will prevent the moni tor from entering the Active Off Power Save Mode without video input The Active Off Mode shuts down the power supply Kill HV Short Gate To Source Yoke Connector Full Operational Testing Position When the HV or the remainder of the protection circuits needs to be
79. shuts off the 5 and 12 power lines to the monitor via IC605 and IC604 The Heater output line turns off the CRT filament voltage IC610 and at the same time turns ON SCR 0616 to activate the Active Off Power mode F601 OFF TH600 DC BIAS TO ON IC502 0519 1001 4 CIRCUIT Q607 IC603 T602 Q605 SWITCHING E POWER SUPPLY COIL PWM 2 SERIAL DATA ISOLATE SW 1 1001 CPU Q609 PROT CIRCUIT SYNC Aen REMOTE ON OFF ABL 200V VERT OUT HEATER ON OFF POWER SUPPLY BLOCK 2 04 1197 1 14 00 14 Active Mode Entry SCR device 0616 starts the Active Off Power Mode The 200V and 8V lines are connected when D616 turns ON The increased voltage on the 8V line requires an immediate correction by the switching power supply IC603 If the 8V line is not restored to 8V within a period of time the power supply IC603 enters the Active Off Power Mode In this mode the oscillator is only operated for a few cycles in bursts This reduction in power drops almost all the switching power supply output voltages The 8V output line to the CPU via IC609 requires so little power it can operate in this low power mode with sufficient voltage Standby regulator circuit Q609 is used to maintain the standby voltage in this Active Off Power Mode Active Off Exit When the computer is turned ON the CPU 1 1001 detects
80. stor types are identified in the Japanese Electronic Industry Asso ciation by the second letter in their number JEIA Nomenclature Standard 25 PNP low power 2SD NPN medium to high power 2SB PNP medium to high 2SK channel FET or MOSFET power 2SC NPN low power 2SJ P channel FET or MOSFET E g 28K3265 is an N channel MOSFET device Static MOSFET Resistance Tests Static MOSFET Out Of Circuit Resistance Tests Gate Source Infinity Infinity Gate Drain Infinity Infinity Drain Source There is often a zener diode connected internally across these terminals Power MOSFET 220 case P or N channel Static MOSFET Conduction Test s Since the static ohmmeter test across a power MOSFET device normally measures infinity you can tell if the device is shorted but not open infin ity To prove this device can conduct is active the ohmmeter can be used to charge the gate for a moment and its Drain to Source conduc tion resistance measured The test procedure for an out of circuit N channel device is 1 Connectthe negative lead of the ohmmeter to the N channel MOSFET SOURCE terminal 2 Touch the ohmmeter s positive lead to the MOSFET s gate terminal to charge it 3 Quickly move the ohmmeter s positive lead to the DRAIN terminal and read the resistance If the device is good you will initially measure a resistance
81. sufficient current to drive the 8 7ohm yoke Output V Sawtooth pulses DC offset voltage DPU The voltages about 1 401 are found in the chart below 10401 Pin Function DC Peak Voltage Wave Shape Voltage 1 DC refinput 1Vp p 2 14V 3 Flyback input 13V 25Vp p 4 14V 5 Saw Output OV 20V saw 40V spike 6 Flyback out 14V 25Vp p 7 Saw Input OV 1Vp p VFBP PROT 1 1001 42 3 2V 5V D BD V SYNC CPU 1 1001 26 D BD 11C SCL FROM CN1006 1 1001 36 37 10803 2 2 LM324 VERTICAL OUTPUT 401 V OUT LA78040 810 CN8o2 CN1005 VERT 1 5 OHMS DEFLECTION PIN NUMBERS ARE YOKE DIFFERENT THAN THE SERVICE MANUAL 11MONO4 1212 1 24 00 54 Horizontal Output Main Horizontal Drive Circuit The purpose of this stage is to create a signal amplify it and feed it to the yoke to magnetically drive or sweep the electron beam across the screen from left to right The computer s horizontal sync signal is input the monitor s CPU to lock match its internal oscillator The DPU receives the CPU s oscillator sig nal and determines the duration length of the sweep The output is amplified to drive the deflection yoke H DY Main Drive Signal Levels AC 72kHz Q 5 70kHz 5Vp p 70kHz 4 70kHz 4Vp p 70kHz 30Vp p 70kHz amp 7V spike
82. sync To wake up the monitor from the Active Off Mode CPU IC1001 turns ON the Remote On Off output This places a load on the 8V line The load is sensed by the switching power supply via Q609 1 603 turns on the os cillator full time instead of in bursts This continuous oscillator output provides sufficient power to maintain the 8V line with a full load Protection The CPU monitors several sections and enters the Active Off Low Power Mode to drop power for protection The CPU monitors the following cir cuits Circuits Monitored LED Indication Both Green and Orange LEDs blink at 1 Hz Both LEDs blink ON 1 sec OFF 2 sec Both LEDs ON 2 sec OFF 1 sec Circuits HV Regulator Circuit Excessive Flyback voltage RGB Cutoff Circuit Excessive ABL Voltage Vertical and Horizontal Output 15 Although a failure in any one of these circuits can trigger the Active Off Power Mode the CPU will indicate the defective circuit using the front panel LED F601 OFF TH600 DC BIAS TO ON IC502 0519 1001 4 CIRCUIT Q607 IC603 T602 Q605 SWITCHING E POWER SUPPLY COIL PWM 2 SERIAL DATA ISOLATE SW 1 1001 CPU Q609 PROT CIRCUIT SYNC Aen REMOTE ON OFF ABL 200V VERT OUT HEATER ON OFF POWER SUPPLY BLOCK 2 04 1197 1 14 00 16 Degaussing Surge Protection AC Input Th
83. tabilize the output voltage permits IC603 to select the same or another operating mode Power Supply Operating Modes Mode Oscillator Characteristic Frequency 1 Normal 63kHz Continuous 63kHz oscillator e g bright signal Duty cycle is changed for screen regulation 2 Light e g 26kHz Continuous 26kHz oscillator screen signal Duty cycle is changed for saver regulation 3 Active off 18 2kHz 6Hz burst rate 18 5msec bursts of 18 2kHz 6 times second The 18 2kHz is PWM Start Up Normal Mode When the front panel power switch is pressed 170 is applied through fusible resistor R625 to the switching oscillator stage This voltage is evident at the SRT T602 transformer primary windings Q605 D and IC603 pin 1 Oscillation does not start until 14 receives voltage The following start up sequence occurs to power the monitor 1 2 Switching Regulator IC603 pin 14 receives a voltage above 2 5V IC603 pin 14 is labeled OOD for On Off Data Voltage input from IC603 pin 1 is permitted to leave Vaux 603 6 to charge external capacitor C613 until IC603 s oscillator runs Vaux is the supply input for the IC like Vcc C613 must continue to supply power to the IC until the power supply stage develops voltage to keep C613 charged 603 internal oscillator starts and approximately 65kHz is output IC603 pin 4 chi ady
84. tested the monitor must be fully powered Hints and Tips The D board shield must be removed for access to the D board from the foil side for troubleshooting Rest the D board on a piece of foam keeping the ON OFF switch exposed Cover the glass line fuse with tape to prevent it from shorting to the A board metal chassis Make sure all boards have a secure black wire ground connection A clothespin can be placed on the heat sink to improve vertical D board stability when probing Full Operation Test Position
85. the same brightness level when new This compensates for reduced CRT cathode efficiency due to ag ing Image restoration operation occurs in three steps White screen implementation CRT Cathode current Measurement Drive level balancing White screen When image restoration is activated the screen is turned white using the OSD 1 003 output that is inserted into the video signal path CPU 1001 sends data to 1 003 to create the full white screen for a few seconds during the operation 003 inserts the white screen information into the 1 001 1 002 video signal path This white video signal should rep resent peak white Meanwhile the R G and B cathode current is moni tored by 1 004 R OUT FROM 1 008 27 30 355 G OUT RGB OUT LM24026 B OUT B 11C FROM 1 1001 36 37 SDA D BD SCL CONT 3 H8D2972 7 0108 128 R108 A 01 tk Li 25V L L REDIkI Gik R115270k FILT FILTER V SYNC IC1001 26 H SYNC 1 1001 27 gt BUFF Q507 E VIDEO OUTPUT 8 04 1210 1 19 00 44 CRT Cathode current Measurement All CRT cathode current must flow through 1 004 A sample of this rent is represented by a signal at 1 004 10 12 Although this signal consists mostly of a DC voltage that corresponds to a white screen the addition of a blanking pulse makes this an AC signal Ik Aging signal 1 004 10 12 Blanking pu
86. tion yoke the focus points form an arc as shown by the arrowheads Early picture tube glass screens were made into a similar arc to maintain focus at the left and right sides of the screen Right side Focus Arc Flat CRT screen Electron beam Left side Picture Tube Top View 61 Modern picture tube screens are flat to reduce annoying room glare This means the focus point must be moved up at the left and right sides to meet the flat picture tube screen Dynamic Focus The job of the dynamic focus circuit is to change the focus points to meet the flat picture tube screen This is done by increasing the static focus voltage when the beam at the left and right sides of the screen This correction voltage is in the shape of a parabola to match the focus arc H Dynamic focus voltage No correction left right Focus correction must be done in the vertical plane for the same reason A vertical dynamic focus waveform is needed as well DF Focus dii FV rivers Focus Digital Processing Unit DPU V amp H DF drivers Dynamic Focus Block Diagram 5 Dynamic Focus Circuit The job of the dynamic focus circuit is to change the focus points to match the flat picture tube screen This is done in the horizontal plane by in creasing the DC focus voltage when the beam at the left and right sides of the screen A similar correction is required in the vertical plane when the beam is at the top
87. tton menu entry serial data and clock signal is applied to OSD IC003 pins and 4 003 generates the requested color menu signal that leaves the RGB signal from pins 14 15 This OSD signal is accompanied by switching signal Fblk from 003 17 43 The OSD signal replaces the RGB video signal using the switch inside RGB Preamp 1 001 The switch is controlled by the Fblk signal from 003 17 Normally without an OSD the switching voltage input IC001 pin 16 is HIGH permitting this IC to pass the normal RGB signal form the computer When the monitor menu is requested the menu appears in the middle of the screen The Fblk signal goes HIGH at this interval to switch the com puter RGB signal out of the video signal path and insert the OSD signal into the video path ALI LIL V blanking menu V blanking The horizontal blanking interval is also provided by this Fblk signal in all modes of operation when the monitor has deflection H amp V deflection sync is necessary for 003 to place an OSD message on the screen either sync signal pulse were missing there would be no OSD and the picture width would not be at the right place Image Restoration This user feature can be menu manually activated after the monitor s green LED is ON for at least 30 minutes The purpose of the image restoration feature is to detect the present cathode efficiency and increase the RGB drive signal to return the CRT to

SONY CPD-G400 Chassis F99 CRT Monitor

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