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Service Manual

XGA COLOR MONITOR

Model : 712B

DAEWOO ELECTRONICS CO., LTD
OVERSEAS SERVICE DEPT.

Summary of Contents for 712B

Page 1: ...ServiceManual XGA COLOR MONITOR Model 712B DAEWOO ELECTRONICS CO LTD OVERSEAS SERVICE DEPT...

Page 2: ...6 GENERAL INFORMATION 7 PIN CONNECTOR 8 CAUTIONS FOR ADJUSTMENT AND REPAIR 8 OPERATION AND ADJUSTMENT 9 ALIGNMENT PROCEDURE 13 TROUBLESHOOTING HINTS 15 BLOCK DIAGRAM 31 PCB LAYOUT 32 SCHEMATIC DIAGRA...

Page 3: ...ntial that these critical parts should be replaced with manufacturer s specified parts to prevent X Ray shock fire or other hazards Do not modify the original design without getting written permission...

Page 4: ...ult in damage to the equipment or other property WARNING Statements identify conditions or practices that could result in personal injury or loss of life Terms as marked on equipment CAUTION Statement...

Page 5: ...o the contacts with a pipe cleaner cotton tipped stick or comparable nonabrasive applicator 10 by volume Aceton and 90 by volume isopropyl alchohol 90 99 strength 6 Do not damage any plug socket B vol...

Page 6: ...ctrically shorted together by conductive foam aluminum foil or comparable conductive material 7 Immediately before removing the protective material from the leads of replacement ES devices touch the p...

Page 7: ...n anti static suction type solder removal device or with desoldering braid before removing the IC Replacement 1 Carefully insert the replacement IC in the circuit board 2 Carefully bend each IC lead a...

Page 8: ...olarity wrap each lead out of the new diode around the corresponding lead on the circuit board 4 Securely crimp each connection and solder it 5 Inspect the solder joints of the two original leads on t...

Page 9: ...rom 50Hz to 160Hz This color monitor supports IBM PC PC XT PC AT personal System 2 PS 2 Apple Macintosh and compatible users crisp text and vivid color graphics display when using the following graphi...

Page 10: ...tment procedure described in the service manual is made by a visual check Allow 20 minutes warm up time for the display before checking or adjusting only electrical specification or function Reform th...

Page 11: ...d function Move cursor to the left window on the OSD window Decrease the value of any selected function Launch OSD On Screen Display MENU window Move cursor to the high window on the OSD window Increa...

Page 12: ...10 Key Process When you choose the icon on the OSD window you can exit the OSD screen Hot Key BRIGHTNESS CONTRAST MENU Start...

Page 13: ...EZOID Degauss the display and restore image quality DEGAUSS Display horizontal vertical frequency and polarity STATUS ICON CONTROL FUNCTIONS Adjust the left and right margins for more convex or more c...

Page 14: ...OSD 5 languages LANGUAGE ICON CONTROL FUNCTIONS Reset the screen to the Factory Preset Display Settings RECALL Adjust the vertical picture moire cancellation V MOIRE Adjust the horizontal picture moir...

Page 15: ...ezoid Receive the cross hatch pattern of Factory preset mode H size V size H phase V position Pincushion Trapezoid are adjusted at each mode In Factory Auto Alignment was done at each mode Therefore F...

Page 16: ...ocus from the best over all focus on the display Also adjust the brightness to the desired condition c Vertical red and blue lines are converged by varying the angles between the two tabs of the 4 pol...

Page 17: ...their ambient circuit Trouble in 12Vdc line of the Main PWB Check the clamping pulse circuit Check the signal cable No Character Is whole screen bright Yes Yes Yes Yes Yes No No No No No Yes Yes Rk Gk...

Page 18: ...U Refer to trouble in power supply unit Is CRT heater red hot No No No No No No No Yes Yes Yes Yes Yes Yes Yes Yes Is Heater Voltage CRT PWB about 6V Turn the Brightness Contrast control to set Maximu...

Page 19: ...grid G1 G2 voltage normal Is the output of pre amp IC801 KA2500 pin 21 24 26 all normal Check video signal cable or video card Trouble in IC801 or its ambient circuit Trouble in video output circuit...

Page 20: ...Voltage CRT PWB about 6V Abnormal OSD Font Is the output of IC204 pin 13 14 15 normal Trouble in Heater voltage line Refer to trouble in P S U Troubie in IC204or its ambient circuit Trouble in IC204...

Page 21: ...n of IC501 Check Q546 and its ambient circuit Trouble in IC501 Trouble in Horizontal output circuit No Raster Yes No Is the Collector wave form of Q541 or Q542 normal Yes Yes Yes Trouble in Q543 and i...

Page 22: ...Picture 6 1 Horizontal Unstable picture Is H Sync input pin of IC501 correct Check H Sync Out of Micom or its ambient circuits Is the pin 1 of IC501 5V Check the value of C514 R516 Yes Yes No No Trou...

Page 23: ...correct Check PWR 13V ambient circuit No Yes Is the output waveform of IC401 pin 6 normal Trouble in V Sync line or IC501 failure Yes No 45Vp p Is the output pulse of IC501 pin 23 normal Yes No Check...

Page 24: ...22 7 Focus Monitor remains unfocused Check Focus VR in FBT Is focus acceptable Trouble in Focus circuit FBT Yes OK No...

Page 25: ...e pin 3 of FBT 2 Check D605 1 Check the 12V DC line 2 Check Q303 Q302 Check after adjusting the static focus finely by VR in FBT DF waveform FVH FVH FVV FVV No Is the base voltage of the Q303 about 2...

Page 26: ...onvergence Is convergence on the center area bad Is convergence on the fringe area bad Adjust static convergence Refer to Adjustment procedure of convergence Yes Adjust D Y Location Yes No Poor conver...

Page 27: ...H size changed No Yes Check pin 15 of IC501 and its ambient circuit D547 R552 R553 C553 It isn t out of order Isthe H Sizeoverscanat60KHz andMax H Size inOSDMenu No Yes 1 Check B section of TDA9111 an...

Page 28: ...DC voltage of IC401 pin 1 Check the IC401 and its ambient circuit Check the IC501 and its ambient circuit No No Trouble V OSC Deflection Circuit Refer to V OSC Deflection circuit Yes Is the 3 5Vdc of...

Page 29: ...Q601 Q605 12V Line Is Q601 collector waveform normal Yes No Trouble in IC601 Is IC601 pin 10 normal Yes No No Trouble in H V circuit No Raster Trouble in IC601 ambient circuit Is the IC601 pin5 H trig...

Page 30: ...O K Select the side pincushion icon on OSD menu and adjust acceptable position Yes Check IC501 or their ambient circuit pin 14 15 16 Is the pin 24 waveform of IC501 correct Yes No Check IC501 or it s...

Page 31: ...e of C104 80Vdc Trouble in D102 or Video Part No Is voltage of C108 120Vdc Trouble in D107 or High Voltage Part No Is voltage of T001 pin 9 130V 370V Trouble in D001 D002 D003 D004 C004 and TH001 No I...

Page 32: ...0 Is voltage of C107 6 3Vdc Trouble in D104 No Is voltage of C114 13Vdc No Yes Yes Yes Is voltage of C121 13Vdc Trouble in D103 or vertical Part P S U O K Trouble in D108 IC102 or horizontal Part No A...

Page 33: ...A2500 VIDEO PREAMP VIDEO OUTPUT LM2407T BIAS CONTROL FBT FFA71012U H VTG B CONTROL KA7500B H DY B CONTROL TDA9111 H OSC V DRV SMPS TRANS POWER IC FILTER SCL SDA SCL SDA OSD R G B SCL SDA H V SYNC SDA...

Page 34: ...32 PCB LAYOUT Main PCB Component Side...

Page 35: ...33 Main PCB Solder Side...

Page 36: ...34 CRT PCB Component Side...

Page 37: ...35 CRT PCB Solder Side...

Page 38: ...36 SCHEMATIC DIAGRAM Power Section...

Page 39: ...37 Micro controller OSD Vertical Section...

Page 40: ...38 Horizontal Section A...

Page 41: ...39 Horizontal Section B...

Page 42: ...40 Video Section...

Page 43: ...41 EXPLODED VIEW MECHANICAL PARTS LIST...

Page 44: ...pF D 0 5 F 1pF J 5 K 10 P 100 0 Z 80 Fig Part No Description Index R101 Resistors RE 42820J Carbon 82J R102 RD 4Z201J Carbon1 4W 200J Allowance F 1 J 5 K 10 M 20 G 2 42 INFORMATION OF PART DESCRIPTION...

Page 45: ...50VRND1MF 5X11 TP 00001 9979800488 PCBMAIN T1 6 330 246 00001 9979800489 PCBVIDEO T1 6 136 105 00150 9970K00012 COREFERRITE RING 23 B002 5PB13857 COILBEAD BI3857 AXIAL B003 5PB13857 COILBEAD BI3857 AX...

Page 46: ...0V CELECTRO 100VRSS22MF 8 11 5 TP C545 CMXL2A104J CMYLAR MEU100V0 1MFJ C547 CEXF2E100V CELECTRO 250VRSS10MF 10X20 TP C548 CMXE2J223J CMYLAR 630VPU0 022MFJ TP C550 CMYH3D532J CMYLAR BUP2KV5300PFJBULK C...

Page 47: ...Y TR KSD471ACY Q542 TKSA539CY TR KSA539CY Q543 TKSC3502E TR KSC3502E D201 DZN4148 DIODE 1N4148AUTO52MM D202 DZN4148 DIODE 1N4148AUTO52MM D301 DRP1H DIODE RP1H D302 DRP1H DIODE RP1H D303 DZN4148 DIODE...

Page 48: ...HMJ R408 RD 2Z279J RCARBONFILM 1 22 7OHMJ R409 RS01Z221J RM OXIDEFILM 1W220OHMJ TAPPING R410 RN AZ8201F RMETALFILM 1 68 2KOHMF R411 RN AZ1471F RMETALFILM 1 61 47KOHMF Q544 TKSD471ACY TR KSD471ACY Q545...

Page 49: ...2012 R705 HRFT562JCA RCHIP 1 105 6KOHMJ2012 R501 RD AZ361J RCARBONFILM 1 6360OHMJ R504 HRFT824JCA RCHIP 1 10820KOHMJ2012 R507 HRFT473JCA RCHIP 1 1047KOHMJ2012 R508 HRFT472JCA RCHIP 1 104 7KOHMJ2012 R5...

Page 50: ...TAP VR603 RV6421104P RSEMIFIXED CCT065AT100KOHMBTAP X201 5XE24R000E CRYSTALQUARTZ HC 49 U24 00000MHZ30PPM R706 HRFT105JCA RCHIP 1 101MOHMJ2012 R707 HRFT562JCA RCHIP 1 105 6KOHMJ2012 R708 HRFT201JCA RC...

Page 51: ...OVERSEAS SERVICE DEPT DAEWOO ELECTRONICS CO LTD 686 AHYEON DONG MAPOGU SEOUL KOREA C P O BOX 8003 SEOUL KOREA TELEX DWELEC K28177 8 CABLE DAEWOOELEC FAX 02 590 6291 TEL 02 360 7114 590 6151 5 http www...

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