Volker Craig VC3100 Service Manual
Contents
1. 3 CHAPTER THO CIRCUIT DESCRIPTION TABLE OF CONTENTS 2 1 INTRODUCTION 2 2 CONTROLLER 1 Address Bus 2 Data Bus 3 Control Pulse Bus 4 Chip Select Bus 2 3 CRT CONTROLLER 3 1 Screen Data Bus 3 2 Scan Counting 3 Character Counting 3 4 Blanking and Drive 2 4 DESCRIPTION OF LOGIC SCHEMATIC DIAGRAMS Schematic 3100 Logie Sheet 1 Schematic 3100 Logic Sheet Schematic 3100 Logic Sheet Schematic 3100 Logic Sheet Schematic 3100 Logic Sheet Schematic 3100 Logic Sheet Schematic 3100 Logic Sheet Schematic 3100 Logic Sheet Schematic 3100 Logic Sheet ow 8 E Ferrer 9 9 9 9 ON OM Fun a 3 an Fu 9 2 5 KEYBOARD 2 5 1 Keyboard Microprocessor 2 5 2 Key Matrix Scanning 2 5 3 Keyboard Output Figure Figure 2 Bus Interconnection Diagran 2 Figure 2 2 2 1 2 Block Diagram of the Address Bus 3 Biock Diagram of the Data Bus Figure 2 4 Block Diagram of the Screen Data Bus Figure 5 Block Diagram of the RD MREQ and WR Signals 6 Block Diagram of the 10REQ Mi and BUSAK Signals Figure 2 7 Block Diagram of the WAITRQ BUSRQ RESET INTRO and NMI Signals Figure 2 5 Format of Output Characters Figure 2 TC2 1 3 4 i 1 y E i 4 ue p D i nn2. 3 2 zi A ort Ss e m o ord 2 2 34 0 f ua 921012 o gt 3 att 2851 2 22 Tore ES M M X 0 2 52 9 vez vel Car SK En I SY n man 2 11 35 2251 azuis 1164 nd 5 903 LI 302 9 2 ze 12 qa e 2 by 45 3L Sanit A3vn 245 Aavn 7 Figure 2 5 Block Diagram of the RD MREQ and WR Signals NABU 3100 Service Manual wee Q a co ee RO ww TTT umm al aem 0 11 amd ne Po 1 11 MET ui umi im 12 NABU Figure 2 6 Block Diagram of the 10REQ Ml and BUSAK Signals i JHL bust vi 43 4 5 3 od 4 202 oft locis 772 377 a 3 5 o o ort 3 o Ul Q 0 m han sel Circuit Description NABU 2 13 538 ap VIINI 225 33 bis 22 Figure 2 7 Block Diagram of the WAITRQ BUSRQ RESET INTRO and NMI Signals Circuit Deseription NABU 3100 Service Manual a rt NABU 3100 Service Manual Circuit Description The RESET signal resets the CPU the UART s the TIMER and the CRT controller to their initial state This signal is generated from the reset switch and Is an external signal
3. 1 4 Edit and Insert Mode Figure 3 8 orar 3 11 Editing Keys Figure 3 18 2 2 a a 3 22 Editing Modes cn nen e Sa ende 3 22 Block Editing Modes naar a ar Sethe A Mate cate 3 22 ESCape Codes which Define GO and Gi Figure 3 19 onen 3 18 Ful Duple FDX Moerse 0 t 8880 4 2 Functional Desctiptohussee eso A EEA ea SENS 1 1 GENERAL 1 11601 25 eas ia 1 1 GLOSSARY OF TERMS 2 eerte A EE 5 1 Graphics Mode Figure 3 10 22 e 3 13 Half Duplex HDX Mode 200 000 a ar E 4 3 861 9 551 01 02 82 0 1000 120 HOW TO BEGIN ee ee EO NOE 2 1 How to Usecthe Manual aan aste nun eat ib 1 1 1510131 15136092019 uren Laget seede bene RA runs 2 1 Installation a eee 2 1 Interrogation Codes is 00000002 4 2 Introduction 1 yea 1 1 Key Functions 7 PU C FERE ELE RP PAUSE NR 3 1 Keyboard Layout Figure 1 1 aera emo 1 5 Local LOC Mode 2 a 4 3 Mata Keyboard 3 1 entlassen EDR 1 4 Monitor Mode Figure 3 11 eee her
4. 2 2 Receive RX and Transmit TX Speeds Figure 3 12 E eiid 3 16 RS232C Parameters ea SE RASRA 4 1 RS232C Pin Assignments for Host Port Table 2 1 0 essere 2 1 Seope and Arrangement dene AS guys 1 1 Screen Alignment Display hence ossa nta 3 26 Screen Background ui ede gU 3 17 Scrolling Region Split Screen 11 3 25 Set Up Mode 35 en ask rn ana 3 7 Set Up Parameters Table 3 1 ii st cota 3 7 Standard Features Se 1 1 Dis C tae 3 4 Status EJne ACCESS anmerken seine einher rn 3 4 Status Line Display weissen 3 4 Status Line Set Up Mode 0 3 7 Status Line Format Figure 3 4 entm 5 3 6 Status Line Set Up 1 nenne Meere 3 7 Status Reset Figure 3 13 rde EEEa 9 945545 3 6 Tab Function Escape Codes asse rra erre ana 3 25
5. 1983 August 3 PRELIMINARY NABU 3100 Service Manual ye A un a A H E o H E 0 A Z A IE en RY he EE RT BITEN A A PEPE er br na EG INDEX Application Keypad Mode Figure 3 6 aaa 3 8 ATtansementzcc ita oe deed 3 1 Audible Feedback 1 1 1 1 aste ase 3 7 Block Editing Modes A aa n a 3 22 Block BLK Mode 4 rass 4 4 Character Attributes MEME 3 17 Character Attributes Figure 3 15 cic sce cence 3 18 Character Presentation On Screen 3 7 Audible Feedback 0 3 7 Character Set Selection idad 3 7 Character Attributes 3 000 2 3 7 Character Width Functions een a 3 17 Screen Background supe vies ur ESAS 3 7 Character Set Selection cones een eaves 3 7 Character Width Functions 22222226 000100 3 17 Communication Commands 4 4 Communication Commands Figure 4 1 sss 4 5 Communications Mode Figure 3 9 tara 3 12 Communication Modes 1 1 1 000
6. ay ee nen ERE enge nen SSR 0 eur ie 2 de GE dr ne en mmm a e ae RT a EEE NABU 3100 Service Manual Circuit Description 2 1 INTRODUCTION The 0 3100 is a direct entry terminal able to transmit and recieve data from a host computer one character at a time or send to a host computer from the keyboard The keyboard translates an input from the key matrix key pressed into a coded binary character compatible with the ASCII code This character is written into the memory of the host computer together with any command bytes which may be necessary for special attributes of the character The host computer responds by transmitting the characters back to the terminal The terminal inspects the command bytes and directs the character to the screen character memory and directs the commands to the attribute memory to determine the visual appearance of the character its c2 ji TO 1 ai The screen scan rate is 10 scan lines per character height and to ensure that only complete characters are displayed on the screen the scan lines are joined by a link list method of accessing memory The list contains the count for the scan lines and resets on the 10th line preventing interru
7. i Table 1 1 Physical Characteristies of the NABU 3100 Table 1 2 Characteristics Of NABU 3100 Interfaces EET H NABU 3100 Service Manual Chapter Content i CHAPTER ONE INTRODUCTION E ER d 1 1 TCT 1 NABU NABU 3100 Service Manual Introduction INTRODUCTION The NABU 3100 Video Display Terminal NABU 3100 shown in Figure 1 1 is a smart data terminal based on the logie of a 2 80 microprocessor The NABU 3100 is capable of communicating with a host computer in either a full duplex or half duplex mode through an interface cable operating under the RS 232C standard rules The standard features of the NABU 3100 are as follows Keyboard Detached with a coiled cable connection to the terminal Full typewriter layout with separate 14 key numeric pad plus cursor control keys Display 24 lines x 80 columns one page of characters Status line 25th line beneath the page user selectable user writeable Display background Grey or optional purchase green or amber Split screen User definable split size Display memory 1 page second page optional purchase Serolling smooth or jump scroll Display characters 7 x 9 dot matrix in a 9 x 10 dot field may be double width on a single line Four different highlights on a character are possible blink bold reverse and with undersco
8. The INTRQ interrupt request signal is generated by the line UART the SPI UART or timer indicating that they require the CPU to perform a specific instruction The CPU completes its current instruction and jumps to read the data at the address given during the interrupt cycle There is a priority order between the three sources as shown below Priority 1 line 7 Priority 2 SPI UART Priority 3 TIMER The NMI non maskable interrupt is a signal generated by the CRT controller to signify the beginning of the CRT vertical retrace interval i i k Chip Select Bus The chip select bus CS bus is part of the addressing function for the memory address Logical combinations of address bits generate chip select signals to access particular memory addresses This method of addressing reduces the number of connecting lines and the number of driver modules NABU 2 14 2 2 4 alii 581 18 iiin i COME C bal ai NABU 3100 Service Manual Circuit Deseription CRT CONTROLLER The CRT controller schedules the information for display on the CRT Screen It breaks each character line into 10 scan lines it also controls refresh timing to ensure that the characters stay visible on the CRT screen for the period of time required by the operator The CRT controller initiates an information write cycle by generating the signal CRTWRT CRT write This signal enables the CRT controller to access
9. SEI TEST DHL iac sce e e IE Db oi n one tantas NPA T SA POR 3 3 0 NABU 3100 Service Manual Troubleshooting And Repair GENERAL This chapter establishes techniques for testing and troubleshooting the NABU 3100 It is important to define the problem area and to apply a logical procedure to isolate the faulty component or components 3 1 NABU VELL Sr 3 1531 Troubleshooting And Repair NABU 3100 Service Manual TROUBLESHOOTING PROCEDURES When troubleshooting the NABU 3100 it is an advantage to carry out a set of procedures in a sequential method to recognize the problem and to locate the faulty component The procedure contains task outlines each with an alphabetical prefix Group A task outline is the primary sequence which will identify the problem area and direct the technician to the next group task outline For any problem it is advisable to start with Group A because it will also identify problem areas for multi fault situations for this reason goup A is called Initial Check Initial Check Group A The initial check of the NABU 3100 is listed sequentially in Table 3 1 NABU 3 2 mv er MI seen TE caer tag v Tess RETT are a ig i T 841 1 EN Biar Ced sp NABU 3100 Service Manual t Troubleshooting And Repair STEP SYMPTOM P
10. 2 4 LOCAL mode incorrect characters on screen If occassionally missing characters the keyboard is faulty A group of characters missing indicates a logic fault Go to 3 2 5 In REMOTE Logic fault Go to 3 2 5 mode transmit and receive data is missing or incorrect For this step a test configuration must be used The terminal under test must be configured as follows a The unit must be in REMOTE mode using SETUP mode or selected at the DIP switches b A known good terminal must be connected to the unit under test through the main serial I O port c Transmit data pin 2 should connect to input pin 3 of good terminal Receive data pin 3 should connect to output pin 2 of good terminal and ground pin 7 should connect to ground pin 7 of good terminal d The baud rates should be the same on both terminals Table 3 1 Initial Check Group A continued NABU 3 1 NABU 3100 Service Manual gt Troubleshooting And Repair Power Supply Group B A DC voltmeter and an AC voltmeter of suitable range are used to verify the operation of the power supply Instead of separate meters a multimeter is acceptable as a test instrument Table 4 2 lists the steps in sequential order STEP POSSIBLE FAULT ACTION The DC voltages are checked at J8 on the Controller PCB 12 pin 1 voltage check If 12 v is not within 5 of nominal VR2 and assoclate
11. 4 1 Opera ON 9 00094 4 1 Conversational Control Functions nnn 4 1 Transmission Control Codes eset 4 1 interrogation Codes A aid ita 4 2 Full Duplex FDX Mode era 4 2 Half Duplex 1 1 1 121 1 1 1212 Saa ek 4 3 Ea eina a E GL Ea 0 ETEEN a S cR E 4 3 Block BEK 1 A f edd 4 4 Communication Commands 49 theater asus 4 4 Cirsor Control Fig re 3 16 3 19 Cursor Control nee Eee oo Re 3 7 Page Records A eee dis 3 21 Cursor Position Indicator utsettelse 3 1 Cursor Position Reporting den 3 21 Cursor Position 1 71 007 3 21 C rsor Position Reporte exse ce ne nen E E 3 1 Deletion Keys and Sequences Figure 3 19 aaa 3 24 Description of Key Functions Figure 3 3 BEIDE ie pde pesa ue Ev TIL AEN Bente leds 3 5 Dip Switch Settings Figure 3 2 222 ee aaa 3 3 Dip SWItehes nee Sa bashes 3 1 Dual Funetion Keypad ee an
12. 4G on the controller PCR i f A driver module to read the settings on the option switches The driver module is located at 21H on the controller module Control Pulse Bus The control pulse CP bus is the highway used by the ontrol signals generated by various functional cireuits of the NABU 3100 The control signals have mnemonic names generally derived from a description of the signal function The major signals using the CP bus are shown in figures 2 5 2 6 and 2 7 NABU 2 6 2 2 3 ee T Sa EEE m BON AE EU Fa ieri o ua p A A A Iit Aq EE Js e 7 GP NABU n 9 6 3 lt Ki 42 0 fa 6 6 6 o E f N 5 i st sank als ps 221 0420910 Brit 46 2 2 65 2 9 8 eL 2 6 2 6 Pile HD 552742 5 ULI uz EDEN 01 51 3421 GESI 7 2 7 damme 25 PEISTAL 22 HI 822738 rai zl 42 tav yrs 2 77 f eot 33224180 3 aaa 2 Circuit Description NABU 3100 Service Manual 110010060 TO Tenue eofados 0015 NAVN cpu 2846 e Cu DRIVE 745347 104 lid SCREEN CHARN DATA See Figur ia SCREEN ATTRIB PATA
13. Keyboard Group D The keyboard is tested when connected to the terminal All supply voltagus for the keyboard are derived from the terminal display unit The keyboard checks are listed sequentially in table 3 4 STEP SYMPTOM POSSIBLE FAULT ACTION Malfunetion of the keyboard identified from Initial Check Group A Connect oscilloscope or logic probe to 3 pin 2 on controller logie PCB Verify that there are pulses on this pin when various keys are operated on the keyboard If there are no pulses on the pin go to step D5 No output from the keyboard Incorrect voltage levels in the keyboard Measure the keyboard power at Z1 between pins 16 and 8 put positive lead on pin 16 the voltage should be between 4 75 and 5 25V dc If there is no voltage eheck the keyboard cable and or power supply in the controller logic PCB If the voltage is out of tolerance check the voltage at J3 pin 1 adjust R25 to obtain 5 15V Table 3 4 Keyboard Group D 3 9 NABU INV ET ER AE LEHE TEEN 26 A 7 AS PLN GLIR or PER en Troubleshooting And Repair NABU 3100 Service Manual STEP SYMPTOM POSSIBLE FAULT ACTION Connect the oscilioscope or logic probe to U5 pin 35 on the keyboard If there are pulses present when Keys are operated the keyboard cable
14. Tab 1 610 15 3 25 Tab Function Escape Codes ses tasse rh a 3 28 Terminal Components REA rra gee dai 1 4 Main Key board s stes 1 1 1 1 1 1 e a ae edet cedo Me 1 4 Dual Function Keypad na ASA 1 4 Video Display Screen oe 1 1 1 1 1 at values gions 1 4 Transmission Control Codes lece Ro aR 4 1 Transmission Delimiter Programming Figure 4 2 4 6 USER NOTES exe anotando a TETE 3 1 User String US Keys sn 1 1 1 en a 3 25 Video Display ee 1 4 3961 inder2 01 02 82 Ro Quo DEV NABU 3100 Service Manual l Preface TRU ACUERDO RR ABT PREFACE QUAM AM The NABU 3100 Service Manual was developed as a complete instruction manual for the NABU 3100 Video Display Terminal Although the technical description and operation is detailed it is assumed that only trained and qualified service technicians will attempt to disassemble or repair the units NABU Manufacturing Corporation has prepared a course of instruction to inform suitable service technicians on repair techniques for the NABU 3100 Video Display Terminal The NABU 3100 Video Display Terminal NABU 3100 is constructed to strict safety sta
15. is faulty and should be changed if there are no pulses go to step D4 Faulty keyboard cable Connect the oscilloscope or logic probe to 21 pin 13 and verify that there is a square wave output If not change the crystal Y1 and or microprocessor zu if necessary Faulty crystal 1 Faulty micro processor 2 No output from micro processor Single keyswitch malfunctioning High resistant Replace contacts contacts Check the keyswitch decoders and replace if necessary Decodes integrated circuits faulty Group of keyswitches malfunctioning Table 3 4 Keyboard Group D continued Controller Logic When it has been established that the controller logie is faulty from Group A use an oscilloscope in conjunction with the schematic diagrams in Appendix A to identify and rectify the fault NABU 3 10 3 2 5 MLN TARIN TE ER 8 EEE ee smm aem tac ED Rl LR rik 8 4 NABU 3100 Service Manual Troubleshooting And Repair DETAILED TROUBLESHOOTING OF MONITOR The monitor in the NABU 3100 is the SAMSUNG unit the troubleshooting techniques are for this monitor If the faulty NABU 3100 contains the MON h monitor refer to Appendix B for details Table 3 5 contains troubleshooting procedures for the SAMSUNG monitor SY
16. of function keys as a top layer A separate key pad is located to the l right of the keyboard Some keys are multi function as defined in the NABU 3100 Users Manual The keyboard contains a micro processor to read the key pads formar z the output coding and perform control functions 2 5 1 Keyboard Microprocessor The keyboard microprocessor contains an integral read only memory ROM with a pre determined program written into the memory This program interprets the key position and designates a code for it this code is output from the microprocessor as a number of bytes of data dependant on the character or function seleoted on the keyboard The program in the microprocessor cannot be altered by the operator The operations performed by the microprocessor are timed by an external erystal oscillator running at 6MHz 2 5 2 Key Matrix Scanning The microprocessor outputs a binary count on its output ports P20 through P23 to the two decoder modules and reads the input ports P11 through P17 When a key is operated the binary count is altered and the signal to the input port is altered The program in the microprocessor identifies these changes and relates them to a code representing the character code The microprocsssor scans the keyboard at a rate proportional to the oscillator and outputs the character code as soon as a change in the matrix is detected 2 5 3 Keyboard Output 1111 When a key
17. using suitable heat sinks 6 Inspect the PCB after soldering for excess solder and shorting of track rectify if necessary T Clean excessive flux from the PCB using a suitable solvent 8 Carry out a functional check of the system after each component change to verify the results a 4 3 NABU en Er A AS reta Sur iro TE 7 de Pisassembly And Repair NABU 3100 Service Manual Keyboard There are no specific repair procedures for the keyboard The follow ing notes are offered as an aid 1 When replacing keysets do not overheat the PCB and use a solder renover to assist in removing keysets 2 To remove key tops pry with fingers only 3 Damaged PCBs should be replaced no attempt should be made ta repair damaged track Display Unit There are no specific repair procedures for the display unit The following notes are offered as an aid 1 It is recommended that the CRT and yoke be changed as a set If either of the components are changed a complete check of the ori entation of the CRT display must be carried out 2 Damaged PCBs should be no attempt should be made to repair damaged track NABU 4 4 2 2 4 2 3 an e ee AE A pe a 12 J EF al Labs alt 111 La a gt Pk IE Rash
18. 00007 3 PCR Assy with space bar less keytops oid 74 250 00007 5 Interchangeable with new new 74 250 00009 1 Hi Tek PCB Assy with spacebar less keytops and microprocessor 59 000 00365 3 or 59 000 0014178 Micro processor 8748 programmed Plunger 15 000 00002 5 Hi tek 173 3 Momentary Plunger 45 000 00009 6 Hi tek 173 0331 Locking 15 000 00010 4 Hi tek 173 140260 Cam looking Spring 2 oz 15 000 000011 1 Hi tek Contact Solid 15 000 00000 9 Hi tek 173 30107 173 30108 Contact Fingered 15 000 00001 2 Hi tek Tool for Contact 97 000 00000 7 Hi tek 173 10023 replacement Cable coiled 24_000 00003 9 BERG 664466 71 Table 6 1 Service Parts List For The Keyboard NABU 6 2 NABU 3100 Service Manual Service Parts List i 6 3 CONTROLLER The controller users standard integrated circuits which have their vendor identification number printed on the top Custom produced items for the controller are listed in Table 6 2 Description Part Number Alternate Source PCB Assy old 71 250 00002 6 new 71 250 00023 9 qa Crystal 81 000 00001 3 Midland Ross HC 18 U 14 7456 MHz Transducer 27 000 00000 4 CGE SSH 01 AHP EPROM U5D 59 000 xxxxX x x programmed on label EPROM U9D 59 000 00412 6 progra
19. EPROM2 27252 ged 2 STD BUS EXPAND Mt 1138 eng eyed Jo 521838146 8 z sandra m 3 fig VN 2 9 c e e ty p lt pa o o 5 E m 101702820 0 aea LT LL lil dil 8 8 CHPAVER 7 foal UA pike Vg ATTA RER 7415377 86 i l 811 u aj ji i ii PE eng PJEG Usados y 39 072122 6 APOE 8Jn8T4 2 c EE NABU 3100 Service Manual Circuit Description ae derivation and use of the signals are as follows RD Read signal is generated by the CPU to indicate that the CPU is in a read state ready to read information from the host computer keyboard serial parallel input port or signals from the timer RD logically AND gated with MREQ memory request will produce MR memory read to tranfer the information is the program memory to the CPU MREQ memory request is generated by the CPU to indicate that the CPU requires informtion from the program memory The address of the specific information will also be on the address bus so that when the memory read signal is generated the program memory will transfer the information to the CPU WR write is generated by the CPU to advise the memory that the CPU is placing information on the data bus This infor
20. K by 12 bit wide memory whose output is copied using the drivers located at 104 12A on the controller PCB to the line buffer memory located at 4A 6A on the controller PCB 2 15 NABU uu SL 2 3 2 3 1 A CDU kan 1 0 T Circuit Description NABU 3100 Service Manual d Simultaneously to event c the screen character data is copied into the character generator module located at 5D on the controller PCB to display the characters as they are copied attribute data is copied to the attribute latch located at 4B on the controller PCB sending attribute information to the video circuits The first two data bytes read out of screen memory contain the information needed to operate the CRT controller the next 80 bytes are character information The CRT controller information required is single or double width characters vertical drive vertical blanking first scan count last scan count line number Scan Counting The screen scan rate is a function of time and to obtain a complete character line complete with any attributes the CRT controller must be able to access screen memory exclusively The CRT controller uses a DMA direct memory access operation to copy the memory contents into the four bit register for the addresses of data for transfer to the drive circuits o
21. LE FAULT ACTION Check grounding wire for poor contact Check video ground wire and power supply wire for incompleteness Check input signal for normality Replace defective parts where required Poor electrical contact Syne noise Picture appears and disappears alternately Poor electrical contact Check input signal Check card edge connector Check video circuit for poor soldering Check CRT socket Check L403 C413 and Qhol Replace defective components where necessary No horizontal linearity Faulty components Check R306 R307 C304 C305 and U301 Replace defeotive components where necessary No vertical linearity Faulty components Check voltages of G2 and G Readjustment of R508 Check high voltage Check CR501 R501 C501 R503 and R509 When all above items check out as normal CRT is faulty and should be replaced Components require adjustment incorrect voltage or faulty CRT Focusing is not achievable Table 3 5 Troubleshooting Chart for the Monitor Continued 3 15 NABU DISASSEMBLE AND REPAIR CHAPTER FOUR e 1 NABU 3100 Service Manual Chapter Content CHAPTER FOUR DISASSEMBLE AND REPAIR TABLE OF CONTENTS 4 1 DISASSEMBLY 4 2 4 1 1 Keyboard 4 2 4 1 2 Display 4 2 4 2 REPAIR 4 3 4 2 1 General 4 3 5 4 2 2 Ke
22. MPTOM POSSIBLE FAULT ACTION No Raster Brightness control Turn brightness control not adjusted R510 elockwise to properly maximum If problem still persists proceed to next step Check CRT heater voltage power supply circuit and CRT socket for normality If problem still persists proceed to next step CRT heater is not functioning f Table 3 5 Troubleshooting Chart for the Monitor 3 11 NABU Troubleshooting And Repair i NABU 3100 Service Manual SYMPTOM POSSIBLE FAULT ACTION N Check flyback transformer 7 Check collector pulse of Check base pulse of 0404 Check collector and base waveforms of Check input HD If all measurements are correct proceed to next step if not replace faulty components 8 41 Vid P Ni GE 13 ttim High voltage not obtainable G2 350V to G4 100V to Gi 100V to 20V K 0 to Check CR501 C501 R501 8507 8505 R503 R508 R509 and No voltage at G2 and GH Check CR502 CR503 R502 R510 R511 R506 C503 C504 E502 and T402 No voltage at Gl No voltage at K Check CR502 R204 R206 E501 and Replace any components in check list found to be faulty Voltages of G2 Replace faulty CRT G4 61 and K are normal No Raster Cont Table 3 5 Troubleshooting Chart f
23. OSSIBLE FAULT ACTION Check security of connector Check that power card is connected to correct power source Cheok that front panel controls are effective Adjust DIP switches according to User Manual SA 1 1 1 TAO incorrect installation No operation AI Dip switch setting incorrect No short beep Go to 3 2 2 1 second when switching on Power supply failure Go to 3 2 5 3 The beep is of 2 second duration when switching on Logie board fault r Go to 3 2 3 Fault in monitor circuit No lights on screen scan lines Characters nonesense data etc TORT A A single Go to 3 2 3 vertical or horizontal line on the screen Fault in monitor eircuit Information on the screen is rolling vertically or horizontally Fault in monitor circuit Go to 3 2 3 Table 3 1 Initial Check Group A 3 3 l NABU ET n EI FA a EE Troubleshooting And Repair NABU 3100 Service Manual STEP SYMPTOM POSSIBLE FAULT ACTION No response at alll Go to ae 2 4 keyboard fault 2 5 Incorrect characters logic fault Incorrect display appears when pressing SET UP key on keyboard With unit in Go to 3
24. The identification and location of components and modules that field service personnel are authorized to replace Appendices NABU iv ee yee eni EG URP NABU 3100 Service Manual Content TABLE OF CONTENTS CHAPTER ONE INTRODUCTION 1 1 INTRODUCTION 1 1 1 2 PHYSICAL CHARACTERISTICS 1 4 1 3 INTERFACE CHARACTERISTICS 1 6 CHAPTER TWO CIRCUIT DESCRIPTION 2 1 INTRODUCTION 2 1 2 2 CONTROLLER 242 2 2 1 Address Bus 2 23 2 2 2 Data Bus 2 5 2 2 3 Control Pulse Bus 2 6 2 2 4 Chip Select Bus 2 14 2 3 CRT CONTROLLER 2 15 2 3 1 Sereen Data Bus 2 15 2 3 2 Sean Counting 2 16 2 3 3 Character Counting 2 17 2 3 4 Blanking and Drive 5 2 17 2 1 DESCRIPTION OF LOGIC SCHEMATIC DIAGRAM 2 18 2 4 1 Schematic 3100 Logic Sheet 1 2 18 2 4 2 Schematic 3100 Logic Sheet 2 2 18 2 4 3 Schematic 3100 Logic Sheet 3 2 19 2 5 4 Schematic 3100 Logic Sheet 4 2 9 2 4 4 Schematic 3100 Logic Sheet 5 2 19 2 4 5 Schematic 3100 Logic Sheet 6 2 20 2 4 6 Schematic 3100 Logic Sheet 7 2 20 2 4 7 Schematic 3100 Logic Sheet 8 2 20 2 4 8 Schematic 3100 Logica Sheet 9 2 20 2 5 KEYBOARD 2 21 2 5 1 Keyboard Microproc ssor 2 21 2 5 2 Key Matrix Scanning 2 gt 21 2 5 3 Keyboard Output 2 21 CHAPTER THREE TROUBLESHOOTING AND REPAIR 3 1 GENERAL 3 1 3 2 TROUBLESHOOTING PROCEDURES 3 2 3 2 1 Initial Check Group A 3 2 3 2 2 Power Supply Group B 3 5 3 2 3 Primary Check of Monitor Group C 3 1 3 2 4 Key
25. accessed by the CPU to perform the functions required 25 d Scratch pad Memory is a read write memory used as a data storage medium for data to and from the host computer e Character memory is a read write memory used to store screen character data f Attribute memory is a read write memory used to store attribute data The major attributes use in the 3100 are double width characters and character highlighting Screen character data drivers copies the output of the character memory onto a line buffer for transmission to the Cathode Ray Tube CRT These drivers are actuated during a CRT copy cycle he Universal Asynchoronous Receiver Transmitters UART s match the CPU transmission rate to the keyboard and the input ports transmission rates The UART s generate the correct signal timing rates i The controller incorporates a set of option switches and their associated drivers to select the options available to the NABU 3100 The major options are change of baud rate data coding and national character sets 2 2 11 LUT E TERE ECI ETI SETT HES OE EE es i 1 Y 3 x Er NABU 3100 Service Manual Circuit Description ae a DC DENN gt circuits to produce and refresh The controller interfaces with video The video circuits are contained the characters on the CRT display on a separate PCB calle
26. ad ol oi nel A EI ET o AS NE a Se CHAPTER FIVE ALIGNMENTS A PN E j ee een dass E 27 ctii do i i in SERVICE PARTS LIST CHAPTER SIX fur dubi Wr A iNT ing in i ci Tor domm iion Care C Die abro No 1 am umi iM Chapter Content CHAPTER SIX SERVICE PARTS LIST TABLE OF CONTENTS INTRODUCTION 6 1 KEYBOARD i 6 2 CONTROLLER 6 3 MONITOR 6 5 Service Parts List For The Keyboard 6 2 Service Parts List For The Controller 6 3 Service Parts List For The SAMSUNG Monitor 6 5 Service Parts List For The MON 4 Monitor 6 6 106 1 NABU NABU 3100 Service Manual 6 2 6 3 6 4 Table Table vike Aiii NABU 3100 Service Manual Service Parts List INTRODUCTION The majority of the components used in the NABU 3100 are industry standard parts easily obtainable through local sources Tne items that are unusual or manufactured by NABU Manufacturing Corporation are identified in this chapter 6 1 NABU iui 81 puo sl E E 8 1 8 UU I dir Service Parts List NABU 3100 Service Manual KEYBOARD Table 6 1 contains the items for the keyboard that are available through NABU Manufacturing Corporation alternate sources are also identified Description Part Number Alternate Source 75 250
27. anual Circuit Deseription The address bus accesses the following modules which are also illustrated in a block diagram form in figure 2 2 a The four EPROM External Programmable Read Only Memory memories which form the Program Memory The EPROM s form a 16K x 8 bit read only memory located at positions 16D 17D 19d and 20D on the controller PCB b The two memory modules forming the Scratch Pad Memory The memory is a 1K x 8bit read write memory located at positions 11B and 16B on the controller PCB ec The eight Random Access Memory RAM modules forming the Character Memory The memory is a 4K x 8 bit read write memory located at positions 12B 13B 18B 158 17B 18B 19B and 20B on the controller PCB i d The four RAM modules forming the Attribute Memory The memory is a 4K x bit read write memory located at positions 178 18B 19A and 20A on the controller PCB e The two decoders forming the memory chip select CS signal decodera The decoders generate the select signals for the appropriate memory The decoders are located at 17F and 19F on the controller PCB f A Buffer module to increae the drive capability of the screen address lines AQ A3 and A5 The Buffer module is located at 16F on the controller PCB g Three Driver modules to drive the screen address lines during the period of time the CRT Controller is copying data from the screen memory to the line buffer memory The Driver modu
28. ays The software timer can interrupt the CPU using the INTRQ signal assuming the interrupt priority enable IEI is a logical one The UART clocks run continuously b The clock pulse oscillator generates the master clock of 14 7456 MHz 2 c The clock pulse divider generates the CPU system clock of 14 7456 MHz or 2 4576 MHz using modules HF 12F 2F and 2G d The bell control is controlled by the I O commands 107 bell on and 108 bell off from modules 2G and 13F e Keyboard and bell clock pulses are generated by 1G an 1F using the system clock pulse as input The keyboard clock is 30 72 KHz the bell clock is 1920 Hz and the timer clock is 960 Hz Schematic 3100 Logic Sheet 5 This sheet contains the connections to the UART s the 1 converters the line output and the optional SPI port output lines 2 19 NABU 2 4 4 ss E EEE ES er II ROR pr ie Circuit Description NABU 3100 Service Manual Schematic 3100 Logic Sheet 6 This sheet contains all the set up and option switch circuits Decoders 14H 16H 19H and 20 H are 3 to 8 decoder modules to select switch sections under the control of address lines AO and Ai using the enable signals CSSW1 or CSSW2 Four switch sections are read in parallel at any one time and the result connected to the CPU address bits 0 and 3 Schematic 3100 Logic Sheet 7 This shee
29. board Group D 3 9 3 2 5 Controller Logic 3 10 3 3 DETAILED TROUBLESHOOTING OF MONITOR 3 11 TC gt 1 NABU Content NABU 3100 Service Manual TABL OF CONTENTS CHAPTER FOUR DISASSEMBLE AND REPAIR 4 1 DISASSEMBLY 1 2 4 1 1 Keyboard 4 2 4 1 2 Display H 2 4 2 REPAIR 4 3 4 2 1 General 4 3 4 2 2 Keyboard 4 4 2 3 Display Unit Ly CHAPTER FIVE ALIGNMENTS 5 1 GENERAL 5 2 5 2 KEYBOARD 5 3 5 3 DISPLAY UNIT 5 0 5 3 1 Brightness Control 5 14 5 3 2 Display Vertical Adjustments 5 4 5 3 3 Display Horizontal Adjustments 5 1 5 3 4 Deflection Yoke Assembly Adjustments 5 6 CHAPTER SIX SERVICE PARTS LIST 7 61 INTRODUCTION 6 1 6 2 KEYBOARD 6 2 6 3 CONTROLLER 6 3 6 4 MONITOR 6 5 APPENDIX 1 Controller Component Layout 1 A 2 Schematic 3100 Logic A 3 3 Monitor Component Layout A 1 A 4 Schematic Monitor 12 SAMSUNG A 23 5 Schematic Video Monitor 4 25 A 6 Schematic 3100 Power Supplies A 27 A 6 Schematic Serial Keyboard 29 NABU TC 2 EREY rec 1 ly e AB WE taa perpe Content om r nn NABU 3100 Service Manual LII ar i M Dd E TABLE OF CONTENTS u 1 i i FIGURES i 1 1 NABU 3100 Video Display Terminal 1 2 5 2 1 Bus Interconnection Diagram 2 1 2 2 Block Diagram of the Address Bus 2 7 2 3 Block Diagram of the Data Bus 2 8 2 4 Block Diagram of the Screen Data Bus 2 9 H 2 5 Block Diagram of the RD MREQ a
30. controller PCB verify that the wave form of the vertical drive is within tolerance If the ripple is excessive the 12V power supply is Using a suitable oscilloscope at pin 4 on the With the aid of the schematic diagrams check the operation E controller PCB faulty of the 12 power i verify that the supply H ripple on the Rectify as necessary E 12 supply is less than 200mV E Table 3 3 Primary Check of Monitor Group C 0 3 7 NABU i g E i 5 1 4 4 E Metern een ami es Troubleshooting And Repair NABU 3100 Service Manual STEP TEST POSSIBLE FAULT ACTION Refer to 3 3 to troubleshoot the monitor If there is nothing on the sereen the Video eircuit in the monitor is faulty After adjusting the brightness control to obtain a rectangle of scan lines verify that there is data or a cursor line Refer to 3 3 to troubleshoot the monitor Vertical circuit in monitor faulty Horizontal line only on display Refer to 3 3 to troubleshoot the monitor Horizontal circuit in monitor faulty Vertical line only on display Table 3 3 Primary Check of Monitor Group 6 continued NABU 3 8 NABU 3100 Service Manual l Troubleshooting And Repair 3 2 4
31. cteristics ii shown in Table 1 1 3 CHARACTERISTICS Available versions Eg Standard With keyboard um Receive Only Without keyboard 1 Dimensions W D H Standard c w keyboard 51 5 cm x 55 5 cm x 34 0 cm inr Display Only 42 0 cm x 37 5 cm x 34 0 cm 1 Keyboard 51 5 cm x 22 5 om x 8 5 cm Weight 1 Standard 16 5 kg y Display 13 3 kg 0 Keyboard 3 2 5 External Connections Display 1 91 AC power input J2 Keyboard connector J3 Optional serial data communications interface TA J Serial data communications interface to modem or host E computer 3 Keyboard J1 Connector to display PO Configuration NABU 3100 115v 50 60 Hz NABU 3100 EXP 230v 50 60 Hz po Power Consumption ak NABU 3100 150 130 VAC 50 60 Hz J NABU 3100 EXP 210 260 VAC 50 60 Hz Table 1 1 Physical Characteristics of the NABJ 3100 NABU 1 4 d En NABU 3100 Service Manual Introduction CHARACTERISTICS Fused 1A Fast Blow Overload Protection NABU 3100 NABU 3100 EXP Fused Dual 0 6 Fast Blow Table 1 1 Physical Characteristics of the NABU 3100 Continued r 1 5 NABU FE ee els ES 98 LP ipud 8 EIN iol Liu LEES 118153 T BAN od ERR TT Introduetion NABU 3100 Service Manual INTERFACE CHARACTERISTICS The int
32. d circuit components are faulty Change VR 2 and or the associated diodes and Capacitors 45V pin 2 nominal V is 5 15 voltage check Adjust R25 or change VR3 gt If the voltage is not within 5 of 5 15V the 45V voltage regulator is faulty Adjust 2 or change VRi If the 5V is not within 5 of 5 00V the 5V voltage regulator is faulty 5V pin 4 voltage check Change Mi on Controller PCB If the 12V is not within 5 the reference voltage regulator is faulty 12V pin 5 voltage check Table 3 2 Power Supply Group B 3 5 NABU Troubleshooting And Repair 1 NABU 3100 Service Manual STEP TEST POSSIBLE FAULT ACTION The AC voltages are checked at 11 on the controller PCB 8 pins 1 amp 2 If BV is not Change the voltage check within 25 of transformer 1 nominal the transformer Tl is faulty 13V pins 3 amp 5 If 13V is not Change the voltage check within 25 of transformer 71 nominal the transformer T1 is faulty All voltages 50 Primary wiring Check wiring and or more out of incorrect source voltage tolerance Rectify where necessary is mas mon RN OE NIS Er No voltages at Fuses faulty linej Using the schematic any of the filter open diagrams verify that secondary circuit power the items of the windings of switch or primary pow
33. d the Monitor The controller uses buses to interconnect the functional units of the system there are four major buses the address bus the data bus the control pulse bus and the chip select bus Address Bus The address bus is a 16 bit address bus AG to A15 connecting the functional modules of the NABU 3100 iilustrated in figure 2 1 When the CPU requires data it sends an address through the address bus to identify the location of the data required by the operating program NABU 2 2 1 f E H i i 248 2 1 48 To 4 T t i X n H a E i E a x a 4 a NABU Bus Interconnection Diagram Figure 2 1 O D TIR EG ML YF iM a AARS ire men 4102213 j dr ALISS2ANI 07 NEE 2 DE 139 Sng asm Tom 0 2 P waren v 21907 P 3ng 55270 1 Nad NEN vrud nomad naayos 21907 03128 JIRI le 3 225 sng noL NOI eng veud vd 0535 rid i 11 11 8 HRI o Tig t egt gestr n P C E r4 d 2 e o o gt u o ul e e i ae rm ta Circuit Description ern NABU 3100 Service M
34. disabled by removing the ground connection at 14F pin 12 Schematic 3100 Logic Sheet 2 This sheet contains the memory chip selection generating circuits the EPROM memory the scratch pad memory and the screen chip selection combining circuit The CRT controller reads character and attribute data from memory as a 12 bit word Screen character data is addressed from 8000 to 8FFF hexidecimal and attribute data from 9000 to 9FFF hexidecimal The CRT controller can only address the 8000 series addresses and uses the combining circuit to address the attributes concurrently with screen characters NABU 2 18 2 4 1 2 4 2 NABU 3100 Service Manual i Circuit Deseription Schematic 3100 Logic Sheet 3 This sheet contains the screen memory and memory data I O circuits The 12 bit data word for the CRT line buffer memory are derived from drivers 10A 11A and 124 during CRT write time Schematic 3100 Logic Sheet This sheet contains the counter timer the clock pulse oscillator the elock pulse divider the bell control and the keyboard and bell clock pulses a The counter timer 4G generates the three UART clocks and a Programmable interrupt time delay It consists of four independant timers programmed form the CPU The three UART clock timers use the system clock pulse to provide clock outputs at pins 7 8 9 The software timer uses a longer frequency clock input on pin 20 to generate longer time del
35. er input function transformer Ti wiring faulty correctly Replace where necessary On regulator heatsink assembly bolted to chassis Table 3 2 Power Supply Group B continued NABU 3 6 KVEN STEGER cM notam NABU 3100 Service Manual Troubleshooting And Repair e Primary Check of Monitor Group C E E There are a number of simple checks that can be carried out to verify the condition of the Monitor circuit The checks consider the SAMSUNG Monitor only The information for the MON H Monitor is contained in Appendix B If the Monitor is found faulty it may be further tested by using the information in 3 3 The primary check of the monitor is 8 listed sequentially in Table 3 3 STEP TEST ACTION 01 Using a DC With the aid of the voltmeter schematic diagrams connected to check the power pins 10 and 7 of supply and wiring the edge Rectify as necessary connector verify that the voltage is within tolerance POSSIBLE FAULT If the voltage is not within 11 and 13V the wiring and or power supply is faulty E If the waveform of the vertical driver is not in accordance with Figure 3 1 the drive circuit is faulty With the ald of the schematic diagrams check vertical driver amplifier and driver Rectify as necessary Using a suitable oscilloscope at J pin 2 on the
36. ere are no special disassembly or assembly instructions required for the display The following notes are offered as an aie With the power cord removed remove two screws at the rear of the cover partially remove the cover remove the ground wire and then totally remove the cover Discharge the high tension HT voltage in accordance with the warning label on the cathode ray tube CRT Removal of the printed circuit boards is straightforward Do not remove the yoke from the CRT unless absolutely necessary Removal of the CRT complete with yoke is straightforward 1 NABU 4 2 Mott mmm 1 i I NABU 3100 Service Manual Disassembly And Repair O mn CAUTION Use a low voltage low wattage soldering iron to effect repairs on printed circuit boards Ensure that the soldering iron is correctly grounded before 4 2 1 General When replacing integrated circuits ICs or transistors that are sol dered onto the printed circuit board PCB observe the following procedures 1 Using diagonal cutters cut the connections of the faulty compo nent and discard 2 Remove the remaining connections on the PCB using a soldering iron and tweezers Do not use excessive heat 3 Use a solder remover to clear the component mounting holes 4 Preform the wire connections on the components prior to position ing on the PCB 5 During the soldering phase protect the components
37. erface characteristics of the NABU 3100 are as shown in Table 1 2 Interface Cables J2 terminal to keyboard Conforms to Standard RS 232C CCITT V 23 Current Loop Adaptor Cable Special 20 mA consumption J3 to peripherals Conforms to Standard RS 123 J to host computer Conforms to Standard RS N23 Communication from JH ASCII and ANSI x 3 64 compatible Escape Sequences Code Serial Asynchronous switchable XON XOFF or DTR control from local or host computer Type Speed 50 to 19200 baud split send receive Method Sequential character in Conversational mode or by line message or page in Buffered Transmit mode Fuil Duplex Half Duplex or Echoplex Mode 7 or 8 bit selectable Character length Parity Odd Even None selectable Table 1 2 Characteristics Of NABU 3100 Interfaces NABU 1 6 1 3 C A 1 0 E 8 18 j di 8 22 ja par i I uM 1 I i 1 CIRCUIT DESCRIPTION CHAPTER TWO er 48 A E Sl EE DE LLL 77 TMI EG rn Chapter Content NABU 3100 Service Manual 12 13 22 NABU fo TO I NN 1
38. f the CRT There are two four bit registers USB on the controller PCB loaded from the screen memory the Last Scan No Register and the line Attribute Latch The Last Scan No Register contains the number of the last horizontal scan in the current character row The contents of this register is fed to the Sean Count Comparator U8A on the controller PCB where it is compared for equality to the contents of the current Scan Counter U9A on the controller PCB The Scan Counter is loaded during the start of a DMA operation with the number of the first horizontal scan of the current character row This counter is incremented as each horizontal scan of the character row is displayed When the contents of the counter equals the output of the Last Sean No Register the Sean Count Comparator sends a signal to the First Scan Latch to indicate that the current character row is complete and the CRT controller then finishes the DMA copy operation allowing access to the screen memory The operation waits on an instruction to commence the DMA cycle for the next character row NABU 2 36 2 3 2 i at ha n a 111785 11 E 2 NABU 3100 Service Manual 0 Circuit Description The Line Attribute Latch contains the addresses of the attributes affecting the entire character row Character Counting During each horizontal scan a character position counter is incremented with the address of the character an its attr
39. ibute to place each character in its correct format and position on the CRT screen The Character Line No Latch U9B on the controller PCB is an 8 bit register which is also loaded during the CRT Controller DMA operations contains the current character row number being displayed The character row number is used by the Address Compressor UIOD on the Controller PCB to generate the screen memory addresses for which the character row will be assembled for display on the CRT The most significant two bits of the Character Line No Lateh determine whioh pair of screen memory pages will be used for display The character row number is incremented by the Character Counter and the Character Counter Latch UTB and U9d on th controller PCB by forming a state machine supplying a binary count for the 80 displayed characters the horizontal blanking signal and the link list addresssing sequence The timing of counters and registers loaded during the CRT controller DMA operations are clocked at the edge of the horizontal blanking signal The horizontal blanking signal is delayed through the Line Attribute Timing Latch U50 on the controller PCB to cause clocking to occur at the correct time Blanking and Drive The Horizontal Drive Logic UllF U15F and U21B on the controller PCB the Double Width Logic UliP and U13F on the controller PCB and the Line Attribute timing Latch combine the vertical blanking the decoded character counter sta
40. id BINE ei um we 920 E m A 0 E m E tees 6 5 NABU t Service Parts List NABU 3100 Service Manual Description Part Nunber Alternate Source PCB Assy 71 250 00031 8 Flyback Transformer 29 250 00001 2 TOTOXU TMF108 Width Coil 29 040 40301 0 Yoke Assy 74 000 00017 1 90 000 00002 7 TOTOKU TKD 2703 Yoke Only 30 904 12000 7 30 931 12000 3 30 900 2300 7 PHILIPS 12ST5470J PH PHILIPS 12ST5470P31J PHILIPS 12ST5470PLAJ CRT White Green Amber Table 6 4 Service Parts List For The MON Monitor NABU 6 6 Wand sr APPENDIX PT 9 T NABU 3100 Service Manual Content APPENDIX TABLE OF CONTENTS APPENDIX A 1 Controller Component Layout 14 A 2 Schematic 3100 Logic A 3 A 3 Monitor Component Layout A 1 A 4 Schematic Monitor 121 SAMSUNG 23 A 5 Schematic Video Monitor 4 5 A 6 Schematic 3100 Power Supplies A 27 6 Schematic Serial Keyboard A 29 NABU TCA 1
41. is operated a two or three byte transmission of data will occur These bytes wil be status and data as shown in Figure 2 5 Diodes are connected to the ends of the matrix to prevent phanton output characters on 2 1 NABU Circuit Description NABU 3100 Service Manual J Status Q Local Full E Page Print Status 7 5 Data 77 Shift Capslock Repeat Logical Games Mode XY Ready Position Not Used or Control D7FH Figure 2 5 Format of Output Characters NABU 2 22 cx 1 teraj ta 5 i i i CHAPTER THREE TROUBLESHOOTING AND REPATR NABU 3100 Service Manual l Chapter Content g o ou nnnm CHAPTER THREE TROUBLESHOOTING AND REPAIR i TABLE OF CONTENTS 3 1 GENERAL 3 1 1 3 2 TROUBLESHOOTING PROCEDURES 3 2 3 2 1 Initial Check Group A 3 2 3 2 2 Power Supply Group 8 3 5 a 3 2 3 Primary Check of Monitor Group C 3 7 a 3 2 4 Keyboard Group D 3 9 3 2 5 Controlier Logic 3 10 3 3 DETAILED TROUBLESHOOTING OF MONITOR 3 11 Table 1 Initial Check Group A 3 3 Table 3 2 Power Supply Group B 3 5 Table 3 3 Primary Check of Monitor Group C 3 7 Table 3 4 Keyboard Group D 3 9 3 Table 3 5 Troubleshooting Chart for the Monitor 3 11 1 5 TC3 1 NABU po we Be n NE PEN ET De o goce PSI NET
42. les are located at 72D 13D and 15D on the controller PCB Data Bus The data bus is connected to the input output connections of the addressable memories described in 2 2 and illustrated in figure 2 1 Data is channelled through the data bus to form the characters displayed on the CRT screen A link list method of access to data ensures that a character scan is completed before accessing a new character line A block diagram of the data bus is shown in figure 2 3 and 2 4 the data bus is directly connected to the screen data bus 2 5 NABU 2 2 2 e diii ik gt 1 li dac Circuit Description NABU 3100 Service Manual The data bus also has access to the following controlling circuits A Two driver modules used to copy the output of the screen character memory into the line buffer memory during a CRT copy cycle The driver modules are located at 10A and 11A on the controller PCB b A Driver module used to copy the outnut of screen data memory into the line buffer memory during a CRT copy cycle The driver module is located a 10B on the controller PCB c A dual UART module connecting the CPU to the line and to the keyboard The UART module is located at TF on the controller PCB e A programmer timer module used to generate three UART clock pulses and one software timing function to control the operation of the various UARTts in the controller The programmer timer module is located at
43. mation will be written into the random access memory RAM module which has been addressed on the address bus 08 9 I O request is generated by the CPU to indicate that the CPU is performing an input output operation from the line UART the SPI UART or the timer circuit The M1 memory cycle 1 signal generated by the CPU is used by the I O dervies to transfer information The signal informs the 1 0 dervices that their interrupt request has been accepted The BUSAK bus acknowledge signal is generated by the CPU when it has finished an operation and has released control of the address and data buses The address and data buses wili then be available to any other device Normally a CRT write signal will be used as a result of the BUSAK signal to start the first scan on the CRT screen The WAITRQ wait request signal is generated by the CPU it isa scheduling signal to suspend read or write operations between the memories and the CPU Normally memory access times are fast enough to ensure that WAITRQ cycles are not required Although this signal is connected to the line UART and the SPI UART modules it is not used by them The BUSRQ bus request signal generated by the CRT controller when it wants to start a CRT write cycle The signal causes the CPU to suspend operations after the completion of the current instruction and thereby release control of the address and data buses As b Ce NABU 2 10
44. mmed PROM 59 000 00413 9 programmed EPROMS U16D 7172 U19D U20D Programmed xxxxx x on label 59 000 xxxxx x 13 000 00035 5 Transformer Assy Transformer Only 29 000 00000 0 Keyboard 74 250 00004 6 Connector Assy O nad EE I TE TET ao o Table 2 Service Parts List For The Controller 6 3 NABU Service Parts List NABU 3100 Service Manual Part Number Alternate Source Keyboard BERG 65903 008 Connector Only 52 000 00001 4 74 000 00008 9 Contrast Control Assy Contrast Control 51 000 00000 1 Only Table 6 2 Service Parts List For The Controller continued NABU 3100 Service Manual Service Parts List On MONITOR The monitor assembly is one of two types SAMSUNG or MON l identifable by the part number on the PCH assembly Custom produced items for the monitor are listed in Tables 6 3 and 6 4 Description Part Number Alternate Source PCB Assy 74 000 00042 1 SAMSUNG 00 05 905 Flyback 29 000 00009 7 SAMSUNG 542 03 1 Transformer Horizontal Output 84 100 53407 9 SGS ATES Transistor Vertical 59 000 00014831 SGS ATES 5 Processor IC Yoke Assy 74 000 00043 4 SAMSUNG 000 01 7 CRT White 30 000 00012 8 SAMSUNG 127248 Green 30 000 00013 1 1 SAMSUNG 12ZBY31 Amber 30 000 000 14 4 SAMSUNG Table 6 3 Service Parts List For The SAMSUNG Monitor v
45. nd WR i Signals 2 31 2 2 6 Block Diagram of the 08 M1 and z BUSAK Signals 2 2 2 7 Block Diagram of the WAITRQ BUSRQ RESET INTRO and NMI Signals 2 13 2 5 Format of Output Characters 2 22 5 1 Location of Adjustments on the Monitor Board 5 5 5 2 Location of Deflection Yoke and Magnets 5 7 TABLES 1 Physical Characteristics of the NABU 3100 Characteristics Of NABU 3100 Interfaces Initial Check Group A Power Supply Group B Primary Check of Monitor Group C Keyboard Group D Troubleshooting Chart for the Monitor Service Parts List For The Keyboard Service Parts List For The Controller Service Parts List For The SAMSUNG Monitor Service Parts List For The MON 4 Monitor 1 1 1 1 mA 9 5 2 UY ot 1 1 1 1 1 OY Ul LO 3 ane 1 1 DO 6 WWW LO ma e FU N i Ti jei GL 83 BENI SR 10 3 NABU CHAPTER ONE INTRODUCTION HO zu mm m s BT ss RS m ai d B n W i 8 1 ith soU BRA e STEPAN i pad 2 0 n TABLE OF CONTESTS 1 1 INTRODUCTION 1 41 Met rn 12 PHYSICAL CHARACTERISTICS dud 1 3 INTERFACE CHARACTERISTICS 1 6 t m Figure 1 1 NABU 3100 Video Display Terminal ger
46. ndards but very high voltagea are generated within the display unit which could be a hazard to life therefore great care should be exercised when removing the covers of the NABU 3100 Covers should only be removed when the supply cord is disconnected The NABU 3100 Service Manual is organized in a logical fashion using the foliowing format Chapter 1 ete GE a e FUR 8 A TE i Introduction A general introduction to the manual its scope and purpose The physical and functional characteristics are also included in this chapter Kite Chapter 2 Description and Operation technical description and operation of the NABU 3100 in a modular manner Each module is described in its relative position of importance within the terminal PRECES ONERE waere Chapter 3 022000 nr a thi pg 0 37 NKI A EAT Testing And Troubleshooting A logical approach to defining and identifying a fault or malfunction within the NABU 3100 ETER Fn EE O ons iii NABU Preface NABU 3100 Service Manual Chapter 4 Disassembly And Repair The correct methods of disassembling and assembling the modules of the NABU 3100 Chapter 5 Alignments The alignment procedures presented in a logical sequence that must be carried out after replacement of defective modules or components Chapter 6 Illustrated Parts List
47. or the Monitor Continued eR UB UL D T LAT NABU 3 12 DT PET ETT U NABU 3100 Service Manual E Troubleshooting And Repair SYMPTOM POSSIBLE FAULT ACTION Defleetion yoke vertical coil is not Only one raster line appears in horizontal direction Replace Only one raster line appears in vertical direction Wire breakdown defective yoke horizontal coil or L402 L403 or C413 open Replace Deformed raster Replace entire deflection yoke Shorting of deflection yoke coil Abnormal raster movement or excessive picture fluctuation Abnormal power supply current surges or alternating magnetic field near unit Check and measure that the ripples of power supply are less than 10mV p p If ripples are normal check for intruding magnetic source Check C502 C503 and CRT for deterioration Replace when necessary Spot remains when power turned off Defective components Check voltage of G2 heater Q201 E501 R503 R204 R205 CR502 and C502 Replace defective components when necessary Brightness range is abnormal Deterioration of CR503 C503 or CRT Check Ch09 C410 and 7402 Replace defective components Raster size is too small and
48. picture is too bright High voltage is abnormally high Table 3 5 Troubleshooting Chart for the Monitor Continued 3 3 NABU Troubleshooting And Repair NABU 3100 Service Manual SYMPTOM POSSIBLE FAULT ACTION Check VD C301 R302 and U301 8 Adjust VD and if problem persists replace defective components No vertical synchronization Vertical deviation is abnormal Deviated raster position Magnet needs centering Turn deflection yoke centering magnet so that raster is positioned at center Check 0201 and associated components Check video input signal Check CRT Picture or characters do not appear no contrast achievable Faulty components or CRT Yoke out of adjustment Loosen clamp screw on deflection yoke Rectify the inclination by turning the entire deflection yoke Inclined picture and or characters Picture noise or characters shiver Check high voltage portion for leakage Check conneetors for complete contact Voltage leaks or component non contact Picture takes too long to appear gt 15 sec Service life of Replace CRT CRT has been exceeded Table 3 5 Troubleshooting Chart for the Monitor Continued NABU 3 14 NABU 3100 Service Manual Troubleshooting And Repair SYMPTOM POSSIB
49. pts from stopping the character scan There are three memories built into the NABU 3100 one is a read only memory where the operating program is permanently stored another for the attribute information and finally one for a scratch pad 1 memory where incoming data is stored iY RIE EIRP ME 0 88 8 2 1 NABU Circuit Description NABU 3160 Service Manual CONTROLLER The NABU 3100 users a Z 80 microprocessor and its associated program memory to control the functions of the unit at a rate determined by a crystal controlled oscillator operating at 14 7456 MHz The controller contains all of the controlling circuits including the microprocessor and is mounted on a single printed circuit board PCB The circuits use integrated circuits to perform the following functions Central Processing Unit CPU to control the functions of the NABU 3100 The CPU schedules information and determines the routing of information As b Timer to generate master timing signals to gate information between the various blocks of the NABU 3100 The timer and the CPU derive their timing cycle from the 14 7456 MHz crystal oscillator All timing functions are multiples of this frequency and asynchronous signals from the NABU 3100 input ports are translated to conform to this timing cycle c Program Memory contains the operating program of the NABU 3100 it is a read only memory and is
50. re Editing Full editing functions with protected fields User strings 16 user programmable strings on 8 keys Escape sequences ANSI X 3 5ll compatible Transmission Block transmission capability line page and or partial page 1 1 NABU 1 1 181181 ER ow n rn caper CRD tte dn LR OLLI UENIRE TN Introduetion NABU 3100 Service Manual mE Figure 1 1 NABU 3100 Video Display Terminal a EGER NABU 1 2 2m II MEM ND SUE met Kad A GE ee a mat is d L o NABU 3100 Service Manual Introduction Data transmission speeds 15 baud rates from 50 up to 9 600 Transmit and receive speeds are independantly selectable Power Requirements nominal 110 or 220 VAC 60 or 50 Hz depending on the model Optional features that may be purchased are Composite video output Background green or amber Display memory second page National character sets Output bi directional buffered serial peripheral port NABU a MU UE i pe 8n zu SH i i Im Thua a 1 Introduction NABU 3100 Service Manual 5 1 2 PHYSICAL CHARACTERISTICS 3 The NABU 3100 Video Display Terminal has the physical chara
51. ren entere 3 15 NABU3100 Specifications Interface Cables and Options Table 1 1 eens 1 2 Operating Procedites i tsa ee xU 1 3 4 Stan Dis Be Die shee Ocean dace OAS 34 Status Line ACCESS eec ieu sepe ese o P quens 3 4 Operating Switches and Control Figure 3 1 3 2 Operating Switches and Control 4 4 3 1 Power On Off Switch eese 3 1 Dip Switches dut ma ERRARE RARE BEREIT Or 3 1 Operation Modes 1 1 ees uar deer didi cee sa iesu rasta 4 1 Optional Ceattres 0 Dele ius 1 4 Page and Cursor Position Indicator Figure 3 17 enn 3 1 Page Records EEA A O EE T 3 1 Power On Off Switch 12 2 2 3 1 PROGRAMMER NOTES 2 and rta 4 1 Protected Field Mode Figure 3 7 erre ese 5 95 sten 3 10 Purpose ol Terminal eio een en a a 1 1 Rear Panel Video Terminal Input Output Connections Figure 2 1
52. t contains the scan counting and part of the character counting circuits Schematic 3100 Logic Sheet 8 This sheet contains the remainder of the character counting circuit and the blanking and drive circuits Schematic 3100 Logic Sheet 9 This sheet contains the video output circuits The video is set to one of four levels off dim normal bright dependant on the value of the attribute bits and the character selected The screen background can be either black off or white on The module IC retimes the two video channels to eliminate spurious timing dots caused by propagation delays through the attribute logic The ratio of the four video levels is set by the value of resistors RT R10 R11 and R12 The amplitude is set by the values of resistors 88 and R13 Transistor Q2 is an emitter follower providing a variable voltage DC source to drive the video output eiruits The contrast control on the front panel determines the amplitude of the video output by setting the DC voltage level at the base of Q2 Resistor 85 sets the maximum voltage available for the video output and thus the maximum contrast available NABU 2 20 e 2 4 6 2 4 7 2 4 8 NABU 3100 Service Manual Cireuit Description nr UU A eg 2 5 KEYBOARD E The keyboard contains the operator ccntrols of the NABU 3100 terminal The layout of the keys is in a standard GWERTY form with an extra set
53. tes the double width and the horizontal blanking to provide monitor drive signals 2 17 NABU 2 3 3 2 3 4 a ae gy s 5 Ry gt 6 PA ont Rie ee aa Circuit Description NABU 3100 Service Manual EXEC eee DESCRIPTION OF LOGIC SCHEMATIC DIACRAMS This section is a short description of the function and identification of logical circuits in the logic schematic diagrams shown in Appendix A This description will enable a technician to identify the function of a particular area on the schematic diagrams The description is related to the sheet number in the title block of each sheet Schematic 3100 Logic Sheet 1 This sheet contains the CPU its associated logie and the screen address drivers The following major signals are generated on this sheet a Bus Request BUSRQ The BUSRQ signal is produced from the OR gate 15F which allows bus requests either from the CRT controller or from the expansion connector b RESET The RESET signal is generated automatically on power up or from the expansion connector The time duration of the signal is determined by the hysterisis feedback level restorer circuit consisting of R21 C80 and inverters BG and 12F c Non Maskable Interrupt NMI The non maskable interrupt signal is generated by the CRT controller during each vertical retrace time For test purposes this interrupt can be
54. the CRT address and data drivers and to place the address bus under the control of the CRT controller The contents of the data bus is then available for transfer into the line buffer memory CRTWRT also transfers the contents of the character and attribute memories into the line buffer memory forming a 12 bit wide data path containing the character its position on the CRT screen and its attribute Sereen Data Bus The inforamation conveyed on the screen data bus has to take into account a number of conditions The first condition is that there are 10 scan lines to each character line and that the complete line is scanned The next condition is that attributes must be applied at the time the character or characters are built up on the screen The third condition is that a blanking pulse must be generated at the end of each scan line to prevent the flyback trace from being visible on the CRT screen During the first scan of each character row the following events occur to achieve the abcve conditions a The CRT controller activates the bus request signal to suspend operation of the CPU and to release the CPU from the address and data buses b The CRT controller takes control of the address lines using the screen address drivers location 12D 13D AND 15D on the controller PCB to place the memory addresses generated by the controller onto the screen data bus 6 The screen character and attribute memory modules are addressed as a 4
55. yboard Bok H 4 2 3 Display Unit 1 H TC 1 NABU NABU 3100 Service Manual Disassembly And Repair WARNING The voltages used in this equipment are sufficiently high to endanger human life Every reasonable precaution has been observed in design to safeguard the operating personnel The power should be removed completely and high voltage capacitors should be discharged in ac cordance with the instructions printed on the labels adjacent to the source of the high voltage using a shorting bar before carrying out any repair or disassembly gt AGES Cn ege m PS Se a Nae ent i ar fi MN 1 To prevent excessive x ray emissions from the cathode ray tube do not exceed the rated high tension voltage NABU NABU 3100 Service Manual Disassembly And Repair DISASSEMBLY Keyboard There are no special disassembly or assembly instructions required for the keyboard The following notes are offered as an aid To remove the keyboard surround use a wooden pry blade to release the top from the housing Protect keys particularly the SEND ENTER key when removing the keyboard surround 1 2 The keyboard display interface cable can only be removed after the keyboard surround is removed 3 Keys are mounted in function blocks Refer to Chapter 7 for unit blocks lh Assembly is the reverse of disassembly Display Th
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