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TROUBLESHOOTING GUIDE
1. NO POWER
NO POWER (POWER INDICATOR OFF)
CHECK FUSE OK?
NO
TROUBLE IN FUSE (F901)
YES
CHECK C907 VOLTAGE? (AC120V: 170VDC, AC220V: 310VDC)
NO
TROUBLE IN D901, D902, D903, D904
YES
CHECK IC901 PIN 3 WAVEFORM (SQUARE WAVE COMES OUT?)
NO
TROUBLE IN IC901, IC902
YES
CHECK D920, D922, D924, D923, D926 VOLTAGE?
NO
TROUBLE IN D920, D922, D923, D924, D926
YES
TROUBLE IN IC923, IC925, Q922, Q923, Q924, Q926
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2. NO CHARACTER
NO CHARACTER
CHECK IC302 PIN 7, 15, 18, 21(8V) ? YES
NO
TROUBLE IN P302 12V LINE, IC304
CHECK IC302 PIN 6, 8, 10 ?
NO
TROUBLE IN PC SIGNAL, P301 SIGNAL CABLE
YES
CHECK IC302 PIN 16, 19, 22 ?
NO
TROUBLE IN IC302
YES CHECK IC303 PIN 6 (70V) 10 (12V) ?
NO
TROUBLE IN P302 12V LINE/70V LINE
YES
CHECK IC303 PIN 1, 3, 5 ?
NO
TROUBLE IN IC303
YES CHECK R, G, B CATHODE VOLTAGE? YES TROUBLE IN CRT SOCKET TROUBLE IN R338~R341, R344, R345, L302~L304, D307~D310, D312, D313
NO
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3. NO RASTER
NO VIDEO (POWER INDICATOR ON)
CHECK POWER INDICATOR GREEN or ORANGE?
ORANGE
DPM MODE (NO H and/or V SYNC)
GREEN
CHECK D712 ANODE (-120V)?
NO
TROUBLE IN D712
YES
CHECK G1 VOLTAGE? ( 10~20V)
NO
TROUBLE IN Q801~Q806
YES
TROUBLE IN D926, Q925 (6.3V)
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4. NO HORIZONTAL DEFLECTION
NO H-DEFLECTION (ONE VERTICAL LINE)
CHECK Q706?
NO
TROUBLE IN Q706
YES
CHECK B+ VOLTAGE (160V)?
NO
TROUBLE IN 160V LINE
YES
CHECK T701(FBT) PIN 3 (31KHZ 70V, 69KHZ 140V) ?
NO
TROUBLE IN Q717, Q718, Q719, D707
YES
CHECK Q705 COLLECTOR WAVEFORM?
NO
TROUBLE IN Q705
YES
TROUBLE IN T701, P701
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5. TROUBLE IN H-LINEARITY
UNBALANCED OF H-LIN.
CHECK IC401 PIN 18, 19, 20?
NO
TROUBLE IN IC401 (MICOM)
YES
CHECK Q711~Q716?
NO
TROUBLE IN Q711 ~ Q716
YES
CHECK L703?
NO
TROUBLE IN L703
YES
Cs SIGNAL TABLE
HORIZONTAK FREQUENCY(fH)
Cs0 L L L H
Cs1 L L H H
Cs2 L H H H
TROUBLE IN L720, R744
30K ~ 39K ~ 47.5K ~ 62K ~
39K 47.5K 62K 70K
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6. NO VERTICAL DEFLECTION
NO V-DEFLECTION (ONE HORIZONTAL LINE)
CHECK IC601 PIN 3 (15V)?
NO
TROUBLE IN R603, Q601~Q603, 15V LINE
YES
CHECK IC601 PIN 7 (40V)?
NO
TROUBLE IN HIGH-VOLTAGE OUT CIRCUIT, D713
YES
CHECK IC701 PIN 12, 13?
NO
TROUBLE IN IC701
3V
YES
TROUBLE IN IC601, V-CIRCUIT
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7. TROUBLE IN OSD
NO OSD
(ENTER BUTTON MUST BE PRESSED.)
CHECK IC301 B+ ?
NO
TROUBLE IN 5V LINE
DC 5V
YES
CHECK IC301 PIN 5, 10 WAVEFORM?
Pin 10
5V
NO
TROUBLE IN IC601 PIN8 (V-FBP), T701 40V LINE
Pin 5
YES
CHECK IC311 PIN 12 WAVEFORM ?
H+V 5V
NO
TROUBLE IN IC302, IC301
YES
CHECK IC311 PIN 13, 14, 15 ?
H+V 5V
NO
TROUBLE IN IC301, IC302
YES
TROUBLE IN OSD PERIPHERAL CIRCUIT
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8. TROUBLE IN DPM
OFF MODE FAILURE
(NO OFF MODE.)
CHECK IC401 (MICOM) PIN 1, 42 (H/V INPUT) SIGNAL?
INPUT H/V SYNC SIGNAL
CHECK PC, (PC IS NOT GOING INTO DPM OFF MODE)
NO H/V SYNC
CHECK IC401 PIN 6 WAVEFORM?
5V
NO
TROUBLE IN X401
6MHz
YES
CHECK IC401 (MICOM) PIN 9, 12 ? SEE DPM TABLE YES
NO
(DPMF: 0V)
TROUBLE IN IC401 (MICOM)
CHECK B+ LINE (6.3V,15V) ?
NO
TROUBLE IN Q922, Q923, Q925, Q926
YES Mode TROUBLE IN PC Item DPMS H H H L
DPM TABLE DPMF H L L L LED GREEN ORANGE ORANGE ORANGE
NORMAL STAND-BY SUSPEND OFF
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9. NO DEGAUSSING
NO DEGAUSSING
(DEGAUSS ON THE OSD MENU MUST BE PRESSED.)
CHECK IC401 PIN 22 (0V)?
NO
TROUBLE IN IC401 (MICOM)
YES
CHECK Q921 COLLECTOR VOLTAGE? DC 5V YES
NO
TROUBLE IN Q921
CHECK P902, P903?
NO
TROUBLE IN P902, P903
YES
CHECK RL901?
NO
TROUBLE IN RL901
YES TROUBLE IN TH902, DEGAUSSING COIL
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10. NO TILT (NO ROTATION )
NO TILT (NO ROTATION)
CHECK Q504 WAVE FORM ?
NO
TROUBLE IN IC401 (MICOM)
YES
CHECK 15V LINE AND 6.3V LINE ?
NO
TROUBLE IN 15V LINE, 6.3V LINE
YES
CHECK Q503 EMITTER VOLTAGE ?
NO
TROUBLE IN Q501~Q503
YES
TROUBLE IN P501, TILT COIL
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