Service Manual Versions and Revision
Contents
1. 23 11 Checking the panel circuit 2A 12 Checking inverter board circuit 25 3 Recommended Parts List Recommended Parts List 26 Page2 LA vf15 FP15 1523 FP5315 1 Power Board Operation Therory 1 1 1 2 1 7 1 7 1 1 7 2 173 174 175 Line filter consists of C801 T801 C802 C803 C804 C837 C838 It eliminates high frequency interference to meet EMI s requirement Rec amp Filter Bridge diode D801 converts AC source into pulsed DC This pulsed DC is smoothed and filtered by C805 R802 is an NTC negative thermal coefficient resistor used to reduce inrush current to be within safe range Power transformer T802 converts energy for square wave from power source C805 to secondary side to generate 12V and 15V Output The square wave from T802 is rectified by D809 D810 then filtered by C817 C822 to generate 15V and 12V respectively Driver Q803 drive T802 from PWM control of 1801 for power converted FB Negative feedback CKT consists of photo coupler I802 and adjustable regulator 1803 It can maintain output voltages 15V and 12V a2. 5 7 System reset LED control circuit 5 8 EPROM for PNP 6 9 EPROM 6 10 CPU circuit 6 10 1 Dection of POWER switch status 6 10 2 Display mode identification 6 10 3 User control 7 10 4 Control of identification converter LSI IC306 8 10 5 Power ON sequence 9 10 6 Power OFF sequence 10 11 Audio Circuit 11 2 Trouble shooting 1 No displa
3. Page 3 LA vf15 FP15 f1523 FP5315 2 Inverter This unit operates on an output voltage of 15V from power source 21 Regulator Q101 geta 5VDC for 1101 power supply 2 2 UVP Q106 turns off when the Vin is under 10V Then pin 3 of 1101 is pulled low and inverter off immediately That is the under voltage protection 23 Control IC 1101 OZ960S 23 1 Enable When pin 3 of I101 is over 1 5V 1101 works If it is under 1 5V I101 turns off 232 OSC When I101 enabled R108 C115 pin 17 pin18 of I101 determine the operating freguency 2 3 3 SST C104 pin 4 of I102 provides soft start function 234 Ignition R109 pin 8 of I101 provides higher operating frequency for more striking voltage until regulation of feedback of lamp current C103 pin 1 of 1101 determine the striking time 2 3 5 Dimming control The divided voltage of R106 R105 R104 control the duty pulse of burst mode to drive O105 and perform a wide dimming control for the CCFL The burst mode freguency is determined by C116 2 3 6 Regulation Pin 9 pin 10 of 1101 provide regulation of the CCFL current from feedback The non inverting reference pin 10 of 1101 is at 1 25V nominal 2 3 7 Protection Open lamp protection in the ignition period is provided through both pin and pin 2 of I101 Removal of the CCFL during normal operation will trigger Q107 to turns on and shuts off the inverter This is latch function 23 8 Output drivers The configuration p
4. 1303 failure OK F NG Failure point OK Power source v y Fale point Failure point Print wire broke between 1305 pin 4 R and 1303 pin 5 1305 failure Page 21 LA vf15 FP15 f1523 FP5315 9 Checking the DC DC converter circuit 9 1 Check the output of 3 3V line voltage from 1309 pin 4 Is the output FB331 being inputted ees to 1309 pin 1 NG Failure point OK OK Printed wire broke between 1309 pin 1 and FB331 yv Failure point 1309 failure y Failure point Printed wire broke between 1309 pin 4 and 1303 power supply pin 9 2 Check the output of 2 5V line voltage from 1309 pin 5 Is the output F B331 being inputted md to 1309 pin 1 NG Failure point OK OK Printed wire broke between 1309 pin 1 and FB331 yv Failure point 1309 failure Vv Failure point Printed wire broke between 1309 pin 5 and 1303 power supply pin Page 22 LA vf15 FP15 f1523 FP5315 10 No power ON Is there 12V DC supply on pin 1 of P309 NG gt Failure point OK 1 Power board failure 2 1301 failure Vv Is there 5V DC ouput pin of P309 NG gt Failure point OK 1 Power board failure 2 C418 C416 C417 short 3 1309 failure
5. Failure point OK NG gt 1 No R G and B video signal output from host computer Check computer 2 Video signal cable disconnection Check the R G B input signals on 1303 pin 171 167 163 respectively that their level is 0 7Vp p maximum Failure point In case of the Red signal A Green and Blue signal is the same oK NG gt path too 1 Printed wire broke between D Sub R and 1302 pin 171 2 R334 short 3 C339 open 4 R332 open Is the pulse of the TTL level being output to P 307 P308 from the data line of 1303 Failure point oK NG gt 1 Printed wire broke between 1303 data line and P307 P308 2 1303 failure Check pulse of POL HMS2 HMS1 LP STH are output to P308 pin 44 45 46 47 48 at TTL level Failure point OK NG gt 1 Printed wire broke between 1303 and P308 of control line 2 LZ301 LZ312 open orRP303 RP314 open 3 CN301 CN312 short yv Check the pulse of CLKV STV1 are output to P307 pin 7 8 Failure point NG gt OK 1 Printed wire broke between 1303 and P307 of control line 2 R357 R355 open 3 C394 C393 short v Check the CLKH OUTPUT to P308 pin 3 from 1303 pin 115 at TTL level Failure point NG gt 1 Printed wire broke between 1303 pin 115 and P 308 pin 3 OK 2 FB324 open 3 FB325 open 4 C401 short Vv Process Checking the resolution change IC movement section Page 17 LA vf15 FP15 f1523 FP5315 5 NO OSD display Confirm t
6. Data transfer between 308 and host There are two forms of communications protocal In both display capabilities are retrieved by the system software during the boot up and configuration time For the PC platform this software layer is defined in the VESA BIOS Extension Display Data Channel DDC2 standard 9 EPPROM Circuit diagram MAIN PWB 4 7 Data transfer between 1306 24LC16B and 1303 Circuit diagram MAIN PWB page 4 7 1306 is effected through the IIC bus SCL pin 52 and SDA pin 51 of 1303 The data to be transferred to each device are stored in 1306 303 control data OSD related setting data Other control data for service menu 10 CPU circuit Circuit diagram MAIN PWB 4 7 1303 gm2115 embeded microcontroller with parallel ROM interface 1302 The source voltage for the device is 3 3V and 2 5Vthe system clock frequency is 14 318MHz 10 1 Detection of POWER switch status The 1303 identifies the ON status of the two power supplies The identification is made when the power supply is turned off For example if the power supply is turned off with the POWER switch the POWER switch must be turned on when activating the power supply again If the power supply is turned off by pulling out the power cord then this power supply can be turned on by connecting the power cord without pressing the POWER switch 10 2 Display mode identification 10 2 1 Functions 1 Display mode identification The display mode of input
7. y Process Checking the resolution change IC movement section 7 2 Checking the control circuit of vertical sync pulse Check the vertical sync signal on 1304 pin 3 and 6 TTL level Failure point NG OK 1 Video cable may have failed 2 Printed wire broke between P 305 pin 14 and 1304 pin 2 3 FB320 R336 open AA Process Checking the resolution change IC movement section Page 20 LA vf15 FP15 1523 FP5315 8 Checking the resolution change IC movement Is there 3 3V supply on 1302 pin 2 20 37 53 67 81 97 111 129 141 146 150 173 181 187 193 196 164 168 172 and 160 ox NG gt Proceed Checking the DC DC converter circuit section Is there 2 5V supply on 1303 pin 176 182 188 26 88 134 203 153 155 and 199 NG gt Proceed Checking the DC DC converter circuit section yv Is 14 318MHz clock input to 1303 pin 152 at TTL level Is 14 318MHz clock output from at TTL level Fail int a ok NG gt ailure poin ii X301 failure Failure point Print wire broke between X301 and 1303 pin 152 y Is Low Reset pluse signal input to 1303 pin 5 about 10 mesc Ea Check the output Low Reset signal OK Ma from 1305 pin 4 y NG Is 5 0V supplied to 1305 pin 5 Failure point
8. 12 Checking inverter board circuit Check Vin pin is around 15 5V On off pin is over 2V Brightness pin is between OV and 3 7V N OK i gt Itis not inverter problem y Check pin 5 of 1102 is 5V ok NG gt Check Q101 D101 D104 and repair them y Check CN102 CN103 is connected right NG Check CCFL and repair them OK Check pin 3 of 1102 is over 2V NG gt Check 0106 D110 and repair them OK y Check pin 18 of 1102 is triangle pulse NG Check C115 R108 1102 and repair OK them yv Check pin 4 of 1102 there is soft start edge up to 4V and pin 11 12 19 20 there is some pulse output Repair 1102 NG gt OK M Check pin 2 of 1102 there is up to 2V from output detection OK gt Check R120 D108 R116 CR101 NG and repair them y Check full bridge 1101 1103 D102 D103 C123 work right NG a Repair them OK Vv Check transformer T101 work right NG gt Repair them OK y Check detection C124 C118 C126 CR 102 CR103 and like those work right and repair them Page 25 LA vf15 FP15 1523 FP5315 1 Recommended Parts List Note 1 The components identified by A mark are critical for X ray safety Repl
9. y Is there 3 3V and 2 5V output from pin 4 of 1309 and pin 5 OK NG gt Failure point 1 1309 failure Vv Precess section 8 Checking the resolution change IC movement Page 23 LA vf15 FP15 f1523 FP5315 11 Checking the panel power circuit 11 1 Check the output of 6V 18V 49 2V line voltage on R392 FB339 FB340 I NG gt Is the PWM wave on pin 5 of 1311 l gt NG l Check the input voltage of 5V on pin 6 of 1311 are Failure point of oe OK 1 F301 open 2 0308 failure Failure point 1311 failure AA Failure point D321 D322 D323 D324 D320 failure v Failure point 1 Printed wire broke between R392 FB339 FB340 P307 and P 308 11 2 Check the output of 3 6V on FB341 NG ls the input voltage of 9 2V on OK Q310 collector y Failure point Printed wire broke between __NG Process above item 11 1 FB341 and P307 OK U Check adjustable voltage of 3 0V 4 0V on pin 1 of 1312 L NG l Check 3 0V 4 0V on pin 3 of 1312 Failure point OK Ole 1 D325 failure 2 R401 VR1 R399 open Failure point 1312 failure AA Failure point Q310 Q311 failure Page 24 LA vf15 FP15 f1523 FP5315
10. signal is identified based on Table 1 and according to the frequency and polarity HPOL VPOL of horizontal or vertical sync signal presence of the resolution or vertical sync signal and the discrimination signal HSYNC_DETECT VSYNC_DETECT When the mode has been identified through the measurement of horizontal and vertical frequencies the total number of lines is determined with a formula of Horizontal frequency Vertical frequency Total number of lines Final identification can be made by examining the coincidence of the obtained figure with the number of lines for the mode identified from the frequency When the detected frequency if the sync signal has changed the total number of lines should be counted even through it is registor identified frequency in the same mode Then it is necessary to examine whether the preset value for the vertical display position has exceeded the total number of lines If exceeded a maximum value should be set up which does not exceed the vertical display position 2 Out of range This out of range mode is assumed when the frequency of the vertical signal is as specified below Vertical frequency equal to 85Hz into fail save mode Vertical frequency over 85Hz into out of range 3 Power save mode The power save mode is assumed when the horizontal vertical signals are as specified below If there is no horizontal sync signal input If there is no vertical sync signal input Pag
11. Ko Service Manual 15 inch LCD Monitor vf15 FP15 f1523 FP5315 Service Manual Versions and Revision Version Release Date Revision Mar 17 2003 Original release Copyright Trademarks Copyright 2003 LiteOn Technology Corp LiteOn is a registered trademark of LiteOn All Rights Reserved Technology Corp All other trademarks are the property of their This manual may not in whole or in part be respective owners copied photocopied reproduced translated or converted to any electronic or machine readable form without prior written permission of LiteOn Technology Corp vf15 FP15 1523 FP5315 Service Manual O vf15 FP15 f1523 FP5315 1 Circuit 1 Power board operation therory 3 2 Inverter 4 3 Power supply 5 4 On screen circuit 5 5 Video input circuit 5 6 Definition converter LSI peripheral circuit
12. ace these with only the same parts specified 2 Ifyou have spare parts need please check BOM to get the last release part number of flash ROM and related information D316 D318 D312 D310 6414056108 DIODE ZENER MMSZ5232B 5 6B DIODES D311 D313 D314 D315 6412019518 DUAL DIODE MMBD7000 DIODES D324 6413040138 DIODE SCHOTTKY B140 1A 40V SMA D325 6414068098 DIODE ZENER MMSZ5235B 6 8B DIODES Page 26 K LITE ON TECHNOLOGY CORP 5 F No 16 Sec 4 Nanking E Road Taipei Taiwan Tel 886 2 25706999 Fax 886 2 25706888 URL www liteontc com tw Printed in Taiwan
13. e 6 LA vf15 FP15 f1523 FP5315 If the horizontal sync signal is outside the measuring range of gm2115 If the vertical sync signal is outside the measuring range of gm2115 Table 1 Mode Resolution H freg Band Width 1 VGA 720 x 400 70Hz 2 VGA 640 x 480 60Hz 3 VESA 640 X 480 72Hz 4 VESA 640 X 480 75Hz 5 VESA 800 x 600 60Hz 6 VESA 800 x 600 7 VESA 800 x 600 8 108 MAC 832 x 624 75Hz 49 72 57 283 9 118 VESA 1024x768 60Hz 48 36 65 10 157 VESA 1024x768 70Hz 56 48 75 z 11 141 VESA 1024x768 75Hz 60 02 78 75 10 3 User Control 1 Select MENU To enter OSD menu 2 W Down To decrease the value of the parameter in the OSD which has been selected for adjustment V Down Choose the next OSD ICON 3 A Up To increase the value of the parameter in the OSD which has been selected for adjustment A Up Choose the previous OSD ICON Page 7 LA vf15 FP15 f1523 FP5315 10 3 1Related ports of 1303 GPIO3 MANUAL Menu Switch input MENU key Down AUTO key ae l up swith input Up BRI Key 10 3 2Functions Control is effected for the push switches to be used when the user changes the parameters in order to modify the respective setting values Whether the switch has been pressed is identified with the switch input level that is turned L Each switch input port is pulled up at outside of I303 Each parameter is stored in the EEPROM the content
14. e signal is output to the jack P303 112 Audio output The audio signal is output from the jack output terminal P303 of the jack board to the internal speaker system Page ll LA vf15 FP15 f1523 FP5315 1 No display of screen Screen is black color of LED is amber Does OSD display when you push key button When a signal isn t being inputted it is indicated with NO dd HI No SIGNAL INPUT oritis y Proceed No OSD display section i indicated with OUT OF RANGE atthe time of the frequency thatit can t be distinguished v Check if the sync signal from Computer is output and if the video cable is connected normally Input the sync signal of computer or NG OK change the cable y Proceed Checking the resolution change IC movement section Page 12 LA vf15 FP15 1523 FP5315 2 Nothing displays on screen Screen is black color of LED is green Is backlight lit NG gt Refer Checking the backlight unit section yv Check the video cable for failure Check the host for I output signal with all black only Does computer output RGB video signals 1 Change pattern of video signal output on the host NG 2 Reconnectthe video cable OK 3 Change the video cable Check OSD menu is displayed on scre
15. en when you push the MENU key NG gt Next Page OK Proceed Abnormal screen section Page 13 LA vf15 FP15 f1523 FP5315 Continue Check the 3 3 V power are supplied on 1309 pin 4 and 2 5V on pin 5 Check if the voltage on 1309 pin1 that NG is high level DC at 5V Failure point OK OK ne 1 Printed wire broke between P309 and 1309 2 FB327 FB328 or FB331 open yv Failure point 1309 Failure yv 1 Check 18V 3 6V 6V on P307 and 43 3V 2 Check 49 2 V on P308 NG l Refer Checking the panel power circuit OK y Is a dot clock being outputted under the condition that a LCD module is connected to P308 pin 3 Failure point NG y 1 1303 failure 2 Printed wire broke between 1303 and P 308 pin 3 yv Check the pulse of POL HMS2 HMS1 LP STH are output on P 308 pin 44 45 46 47 48 at TTL level Failure point oK NG gt 1 1303 failure 2 Printed wire broke between 1303 and P 308 pin 44 45 46 47 48 Check the CLKV STV1 pulse are output on P307 pin 7 8 Failure point NG OK Pi 1302 failure 2 Printed wire broke between 1303 and P 307 pin 7 8 yv NextPage Page 14 LA vf15 FP15 1523 FP5315 Cont
16. he MENU key is pressed at that moment Failure point 1 Function key is destroyed NG 2 FB305 open OK 3 RP 302 open 4 1303 failure Proceed Checking the resolution change IC movement section Page 18 LA vf15 FP15 1523 FP5315 6 Abnormal plug and play operation Confirm the input of serial clock on 1308 pin 6 SCL at TTL level OK gt Failure point 1308 failure Failure point 1 The video cable may have failed or may not to have connections for DDC 2 Between 1308 pin 6 and P305 pin 12 may have failed 3 R405 R323 open 4 Cable failure Confirm the input of serial data on 1308 pin 5 SDA at TTL level Failure point OK 1308 failure AA Failure point 1 The host machine isn t communicating in DDC mode 2 The video cable may have failed or may not to have connections for DDC 3 Between 1305 pin 5 and P305 pin 11 may have failed 4 R406 R324 open 5 Cable failure Page 19 LA vf15 FP15 f1523 FP5315 7 Checking the interface circuit of sync signal 7 1 Checking the control circuit of horizontal sync pulse Check the horizontal sync signal on 1304 pin 11 and pin 8 TTL level Failure point MG 1 Video cable may have failed OK 2 Printed wire broke between P 305 pin 3 and 1306 pin 11 3 FB311 R334 open
17. inue Check the data signal output on P307 and P308 R G B data pin Failure point OK NG p gt 1 1303 failure 2 Printed wire broke between 1303 and P307 P308 data line yv Failure point 1 The cable broke between P307 P308 and LCD module 2 LCD module failure Page 15 QD 3 Checking the back light unit vf15 FP15 1523 FP5315 Is 12V supplied to CN101 pin 1 2 to inverter PWB NG Failure point Inverter cable disconnection Check the INV_EN signal input to Inverter Board Q104 at TTL high level ca Is a H level being output in the TTL level from 1303 pin 114 Or is INV_EN signal being output OK NG y F ailure point Printed wire broke between 1303 pin 114 and Inverter Board Q104 Vv Check the PWM signal of the input from 1303 pin 40 is a BRI signal Failure point OK NG gt 1 P rinted wire broke between 1303 pin 40 and Q313 Q312 2 1303 failure AA Failure point 1 Inverter of LCD module failure Page 16 LA vf15 FP15 f1523 FP5315 4 Abnormal screen Check the R G B video signal from computer input on D Sub R G B connector
18. ntrol gate IC OFF is generated from I311 3 5 A18V DC power supply for LCD module to control gate IC ON is generated from 1311 3 6 A3 6V DC power supply for LCD module to control panel Gamut of V Com 4 On screen circuit Circuit diagrams Main PWB I303 gm2115 Embeded function On screen menu screen is established and the resultant data are output from I303 Circuit diagram MAIN PWB gm2115 5 Video input circuit Circuit diagram MAIN PWB The AC coupled video signal is used to clamp the black level at 0V 6 Definition converter LSI peripheral circuit Circuit diagram MAIN PWB 1303 gm2115 is the definition converter LSI The analog R G B signal input entered from the video input circuit is converted into the digital data of video signal through the incorporated A D converter Based on this conversion this device performs interpolation during pixel extension The source voltage for this device is 3 3V and 2 5V the system clock frequency is 14 318MHz The withstand voltage level for the input signal voltage is 3 3V and 5V 7 System reset LED control circuit Circuit diagram MAIN PWB 71 System reset System reset is performed by detecting the rising of the 5V source voltage at 1305 72 LED control circuit Green amber is lit with the control signal of the LED GREEN and LEDAMBER signal pin 49 48 from I303 Circuit diagram MAIN PWB Page 5 LA vf15 FP15 f1523 FP5315 8 EPROM for PnP Circuit diagram MAIN PWB 3 7
19. revents any shoot through issue associated with bridge type power conversion applications Adjusting the overlap conduction between 1102 P MOSFET and 1103 N MOSFET I102 N MOSFET and 1103 P MOSFET the CCFL current regulation is achieved 24 _ Full bridgeswitching Transformer 1102 1103 C123 1104 1105 C137 C125 T101 T102 compose full bridge swit ching to convert DC into AC for driver the CCFL 25 Detection C124 C125 C126 detect the output voltage and ensure a rated voltage by pin2 of 1101 Q108 Q109 ensure not a open lamp 2 6 Feedback D119 R123 D120 sense the lamp current for negative feedback and regulation Inverter Circuit VCC Regulator VDD U Control IC 02960 p Fullbridge switching Transformer Lamp ON OFF gt UVP el Enable Output driver Osc Protection Detection m SST Ignition 4 Brightness Dimmi Les ON Regulation Feedback lt Page 4 LA vf15 FP15 1523 FP5315 3 Power supply Circuit diagrams Main PWB 3 1 Line filter consists of FB326 FB327 FB328 It eliminates high frequency interference to meet EMP s requirement 3 2 D093 3V and 2 5V DC DC requlator A3 3V and 2 5V DC power supply for LCD module and ASIC 3 3 A9 2V DC power supply for LCD module source IC is generated from 1311 34 A6VDC power supply for LCD module to co
20. s of which are updated as reguired 10 4 Control of definition converter gm 2115 1303 10 4 1Ports related to control Gm2115 serial data 52 o SCL___ Gm2 115 serial clock 207 HDATA2 Gm2115 Address input HDATAI Gm2115 Address input 10 4 2Functions Major function of 1303 are as follows 1 Expansion of the display screen 2 Timing control for various signal types 3 Power supply sequence LCD panel Page 8 O vf15 FP15 1523 FP5315 10 5 Power ON sequence LCD_ON OFF Low Active LED GREEN High Actwe g 270 msec DCDC_EN High Active 270 msec CLKH 360 msec STH 5 380 msec DATA ee 380 msec INV_EN gt High Active 460 msec Page 9 O vf15 FP15 f1523 FP5315 10 6 Power OFF sequence LCD_ONOFF Low Active LED_GREEN eee 55 msec DCDC_EN a J 260 msec an JUUUL e 170 msec STH lic ll o gt 170 msec DATA BREN lt r 190 msec INV_EN n ___ 100 msec Page 10 LA vf15 FP15 1523 FP5315 11 Audio circuit Circuit diagrams Main PWB 11 1 Audio input The audio signal input received from the audio input terminal P302 is applied to the amplifier I301 of I and 9 through the low pass filter consisting of R305 R306 C314 and C315 In this amplifier controls of Volume are availavle The audio signal controlled at the VR601 determines the attenu ation of output of the amplifiers Since then th
21. t a stable level PWM Start When power is turned on C807 is charged a 15 volt and a starting current above 40uA to pin 7 of I801 1801 starts to oscillate and outputs a pulse train through pin 6 to drive Q803 OPP When Q803 turns on C805 supplies a linearly increasing triangle current through the primary inductance of T802 to the driver Q803 once the peak value of this current multiplied by R811 exceeds volt pulse train will be turn off immediately to protect Q803 T802 from being burned out Regulation If output voltage 15V goes up the R terminal of 1803 gets more bias accordingly photo transistor and photo diode flows more current The voltage of pin 2 goes up too making the pulse width of pin 6 to become narrower So the output voltage 15V will be pulled down to a stable value OVP If 15V goes up too much the induced voltage on pin 4 of T802 becomes large also Suppose that it is over 18 volts ZD801 conducts pin 3 of ISOI is pulled up over 1 volt The pulse train at pin 6 goes down to zero shutting Q803 off immediately SCP If output terminal is short to ground photo transistor does not conduct hence Q806 does not conduct either Then oscillation of 1801 is stop shutting Q803 off immediately HPD K15AA Power Board Block Diagram Line Rec amp Filter gt Filter gt Power Transformer Outpur Rec amp Filter i PWM Driver L FB
22. y of screen Screen is black color of LED is amber 12 2 Nothing displays on screen Screen is black color of LED is green B 3 Checking the back light unit 16 4 Abnormal screen 17 5 No OSD display 18 6 Abnormal plug and play operation 19 7 Checking the interface circuit of sync signal 20 7 1 Checking the control circuit of horizontal sync pulse 20 7 2 Checking the control circuit of vertical sync pulse 20 Page 1 LA vf15 FP15 f1523 FP5315 8 Checking the resolution change IC movement 21 9 Checking the DC DC converter circuit 2 10 No power on
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