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Website:http://biz.LGservice.com
E-mail:http://www.LGEservice.com/techsup.html
Compaq MV7500
SERVICE MANUAL
LG: CA-110
LG CQ771G
MODEL: S7500 (PE1165T), S7500 (PE1165),
MV7500 (PE1165U), MV7500 (PE1165),
CV7500 (PE1165U)
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CONTENTS SPECIFICATIONS ................................................... 2 ADJUSTMENT ...................................................... 10 TROUBLESHOOTING GUIDE .............................. 12 SAFETY PRECAUTIONS ........................................ 3 EXPLODED VIEW................................................... 22 TIMING CHART ....................................................... 4 REPLACEMENT PARTS LIST ............................... 24 OPERATING INSTRUCTIONS ...............
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SAFETY PRECAUTIONS SAFETY-RELATED COMPONENT WARNING! X-RADIATION There are special components used in this color monitor The only potential source of X-radiation is the picture tube. which are important for safety. These parts are marked However, when the high voltage circuitry is operating on the schematic diagram and the replacement properly there is no possibility of an X-radiation problem. parts list. It is essential that these critical parts should be The basic precaution which must be exer
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TIMING CHART VIDEO B A E C F D SYNC << Dot Clock (MHz), Horizontal Frequency (kHz), Vertical Frequency (Hz), Horizontal etc... (µs), Vertical etc... (ms) >> H/V Sync Total Period Video Active Sync Duration Blanking Time Back Porch Front Porch Mode Resolution Frequency (E) Time (A) (D) (F) Sort Polarity (B) (C) H – 37.500 26.667 20.317 6.349 2.032 3.810 0.508 640x480 1 75Hz V – 75.000 13.333 12.800 0.533 0.080 0.427 0.027 H – 31.469 31.778 25.422 6.356 3.813 1.907 0.636 640x480 2 60Hz V – 59.94
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OPERATING INSTRUCTIONS FRONT VIEW REAR VIEW AC Power Socket Signal Connector Power ON/OFF Button See Front Control Panel Front Control Panel 4 2 1 3 4. Select 1. Power/LED Launches on-screen displays, selects functions and Controls power to the monitor. adjustments, and exits menus and On-Screen Display. The LED on the power button is illuminated when the power is on. 5. Hot Key 2. Right Adjustment Left Adjustment Moves clockwise through menu options or increases Just select
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WIRING DIAGRAM P201 P402 P405 P501 P702 S P701 + S T1 AC Socket P902 Signal Cable P302 P301 P303 - 6 - FBT
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BLOCK DIAGRAM Dynamic Focus Static Focus G1 Screen(G2) - 7 - < OSD Control > H.V 80V Heater ( 6.3V ) Signal + MENU H-Sync Sig R POWER Cable VIDEO V-Sync Sig VIDEO G PRE-AMP DY CDT MAIN AMP 2 B I C DATA(SDA) (IC302) (IC303) CONTRAST 2 LM1269 I C CLOCK(SCL) LM2467 BRIGHTNESS H POSITION H SIZE OSD IC MICOM 5V 15V 5V V POSITION 2 (IC301) I C SCL / SDA (IC401) V SIZE NT6872 CUT OFF IC 5V H/V Sync, R/G/B SPCC (IC304) PWM Control Drive/Contrast 2 TRAPEZOID I C LM2480 Cut-Off PIN BALANCE PAR
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DESCRIPTION OF BLOCK DIAGRAM 1. Line Filter & Associated Circuit. 3) The Micom sets operating mode and offers the This is used for suppressing noise of power input line controlled data. (H-size, H-position, V-size, ... etc.) flowing into the monitor and/or some noise generated in 4) The controlled data of each mode is stored in itself. this monitor flowing out through the power input line. 5) User can adjust screen condition by each OSD That is to say, this circuit prevents interference between
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15. H& V Blanking and Brightness Control. 18. Video Pre-Amp Circuit. Blanking circuit eliminates retrace line by supplying This circuit amplifies the analog video signal from 0-0.7V negative pulse to the G1 of the CRT. And Brightness to 0-4V. It is operated by taking the clamp, R, G, B drive circuit is used for control of the screen brightness. and contrast signal from the Micom(IC401). 16. Image Rotation (Tilt) Circuit. 19. Video Output Amp Circuit. This circuit corrects the tilt of the screen
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ADJUSTMENT GENERAL INFORMATION All adjustment are thoroughly checked and corrected 7) Adjust tilt as arrow keys to be the best condition. when the monitor leaves the factory, but sometimes 8) DIST. ADJ. → BALANCE command. several adjustments may be required. 9) Adjust parallelogram as arrow keys to be the best Adjustment should be following procedure and after condition. warming up for a minimum of 30 minutes. 10) Adjust balance of pin-balance as arrow keys to be the best condition. • Alig
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14) Set Brightness is cut-off(0.06FL) and Contrast to 5. Input EDID Data. 1) Display color 15,0 cross hatch pattern at Mode 8. Max position. 2) EEPROM → Write EDID command and confirm 15) Set SUB-CONTRAST Max 127(7F) (decimal) position. “EDID Write OK!!” message of monitor. 16) Set B-DRIVE to 90(5A); LG CDT at DRIVE of the 3) Exit from the alignment program. alignment program. (TECO CDT: B-DRIVE 100(64)) 4) Power switch OFF/ON for EDID data save. 17-1) Adjust R-DRIVE and G-DRIVE command to whit
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TROUBLESHOOTING GUIDE 1. NO POWER NO POWER (POWER INDICATOR OFF) NO CHECK TROUBLE IN FUSE FUSE OK? (F901) YES CHECK C908 VOLTAGE? NO TROUBLE IN (AC120V: 160VDC, D900 AC220V: 304VDC) YES CHECK IC901 PIN 6 NO TROUBLE IN WAVEFORM (SQUARE WAVE IC901 COMES OUT?) YES CHECK TROUBLE IN NO D941, D942, D951, D961, D941, D942, D951, D962, D971 D961, D962, D971 VOLTAGE? YES TROUBLE IN Q903, Q952, Q951, Q942, Q941 - 12 -
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2. NO CHARACTER NO CHARACTER CHECK TROUBLE IN NO IC302 P302 5V LINE PIN 9(5V) ? YES TROUBLE IN CHECK NO PC SIGNAL, IC302 PIN 5, 6, 7? P301 SIGNAL CABLE YES CHECK NO TROUBLE IN IC302 PIN 20, 19, 18 ? IC302 YES CHECK TROUBLE IN NO IC303 PIN 4 (80V) P303 12V LINE/ PIN 8 (12V) ? 80V LINE YES CHECK NO TROUBLE IN IC303 IC303 PIN 1, 2, 3 ? YES TROUBLE IN CHECK NO R341~R343, R, G, B CATHODE R331~R333, L311~L313, VOLTAGE? D307~D312 YES TROUBLE IN CRT SOCKET - 13 -
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3. NO RASTER NO VIDEO (POWER INDICATOR ON) CHECK AMBER DPM MODE POWER INDICATOR (NO H and/or V SYNC) GREEN or AMBER? GREEN CHECK NO TROUBLE IN D712 ANODE D712 (-157V)? YES CHECK NO TROUBLE IN G1 VOLTAGE? Q799 (-55V~-150V) YES CHECK TROUBLE IN NO CDT HEAT D941, Q942, Q941 VOLTAGE? (6.3V) YES TROUBLE IN CDT - 14 -
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4. NO HORIZONTAL DEFLECTION NO H-DEFLECTION (ONE VERTICAL LINE) NO CHECK TROUBLE IN Q706? Q706 YES CHECK NO TROUBLE IN + B VOLTAGE 50V LINE (50V)? YES CHECK T701(FBT) PIN 2 NO TROUBLE IN (31KHZ 60V, Q719, Q720, D710 69KHZ 140V) ? YES CHECK TROUBLE IN NO Q701 COLLECTOR Q701 WAVEFORM? YES 0V T TROUBLE IN T701, P701 - 15 -
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5. TROUBLE IN H-LINEARITY UNBALANCED OF H-LIN. CHECK NO TROUBLE IN IC401 IC401 (MICOM) PIN 5, 6, 7 ? YES CHECK NO TROUBLE IN Q711~Q716? Q711 ~ Q716 YES CHECK NO TROUBLE IN L703? L703 Cs SIGNAL TABLE YES HORIZONTAL Cs1 Cs2 Cs3 Cs0 FREQUENCY(fH) 30K ~ 33.9K L L L 255 34K ~ 38.9K L H L 155 TROUBLE IN 39K ~ 43.9K H L L 130 C722, C723, C726, C729 44K ~ 47.9K H L H 100 48K ~ 51.9K H L H 85 52K ~ 57.9K H H L 70 58K ~ 61.9K H H L 60 62K ~ 65.9K H H H 60 66K ~ 70K H H H 30 - 16 -
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6. NO VERTICAL DEFLECTION NO V-DEFLECTION (ONE HORIZONTAL LINE) CHECK NO TROUBLE IN IC601 PIN 3 R603 15V LINE (15V)? YES TROUBLE IN CHECK NO HIGH-VOLTAGE OUT IC601 PIN 7 CIRCUIT(FBT), (40V)? D721, R606 YES CHECK NO TROUBLE IN IC701 PIN 12, 13? IC701 3V YES TROUBLE IN IC601, V-CIRCUIT - 17 -
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7. TROUBLE IN OSD NO OSD (ENTER BUTTON MUST BE PRESSED.) CHECK NO TROUBLE IN + IC301 B 5V LINE (5V) ? DC 5V YES CHECK TROUBLE IN NO IC301 PIN 5, 10 IC601 PIN8 (V-FBP), WAVEFORM? T701 40V LINE (H-FBP) Pin 10 5V YES Pin 5 CHECK TROUBLE IN NO IC301 PIN 12 IC302, IC301 WAVEFORM ? H+V 5V YES CHECK NO TROUBLE IN IC301 PIN 13, 14, 15 ? IC301, IC302 H+V 5V YES TROUBLE IN OSD PERIPHERAL CIRCUIT - 18 -
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8. TROUBLE IN DPM (NO OFF MODE.) OFF MODE FAILURE CHECK CHECK PC, IC401 (MICOM) NO INPUT H/V SYNC SIGNAL (PC IS NOT GOING INTO PIN 31, 32 (H/V INPUT) DPM OFF MODE) SIGNAL? YES H/V SYNC CHECK NO TROUBLE IN IC401 PIN 13 X401 WAVEFORM? 5V YES 24MHz CHECK NO (DPMF: 0V) TROUBLE IN IC401 (MICOM) IC401 (MICOM) PIN 2, 3 ? SEE DPM TABLE YES CHECK + NO B LINE TROUBLE IN (6.3V,15V, 80V) ? Q941, Q942, Q951, Q952, YES DPM TABLE Item LED DPMF Mode TROUBLE IN PC GREEN H NORMAL AMBER L
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9. NO DEGAUSSING NO DEGAUSSING (DEGAUSS ON THE OSD MENU MUST BE PRESSED.) CHECK NO TROUBLE IN IC401 PIN 19 IC401 (MICOM) (0V)? YES CHECK NO TROUBLE IN Q953 COLLECTOR Q953 VOLTAGE? DC 15V YES CHECK NO TROUBLE IN P902 ? P902 YES NO CHECK TROUBLE IN RL901? RL901 YES TROUBLE IN TH901, DEGAUSSING COIL - 20 -
