Text preview for : Compaq MV540 CQ550F CO1075 trouble shooting.pdf part of Compaq mv540 Compaq MV540, CQ550F, CO1075
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1. NO POWER
NO POWER (POWER INDICATOR OFF)
CHECK FUSE OK? (F901) YES
NO
TROUBLE IN FUSE (F901)
CHECK C908 VOLTAGE? (AC120V: 160VDC, AC220V: 304VDC)
NO
TROUBLE IN D900
YES
CHECK IC901 PIN 6 WAVEFORM (SQUARE WAVE COMES OUT?)
NO
TROUBLE IN IC901
YES
CHECK D941, D951, D961, D971 VOLTAGE?
NO
TROUBLE IN D941, D951, D961, D971
YES
TROUBLE IN PC901, PC902, IC902, IC904, ZD902, D921, D923, Q903
2. NO CHARACTER
NO CHARACTER
CHECK IC302 PIN 9 (5V) ? YES
NO
TROUBLE IN P302 5V LINE
CHECK IC302 PIN 5, 6, 7 ?
NO
TROUBLE IN PC SIGNAL, P301 SIGNAL CABLE
YES
CHECK IC302 PIN 18, 19, 20 ?
NO
TROUBLE IN IC302
YES CHECK IC303 PIN 4 (80V) PIN 8 (12V) ?
NO
TROUBLE IN P302 12V LINE/ 80V LINE
YES
CHECK IC303 PIN 1, 2, 3 ?
NO
TROUBLE IN IC303
YES CHECK R, G, B CATHODE VOLTAGE? YES TROUBLE IN IC304 / CRT SOCKET TROUBLE IN R341~R343, R331~R333, L311~L313, D307~D315
NO
3. NO RASTER
NO VIDEO (POWER INDICATOR ON)
CHECK POWER INDICATOR GREEN or ORANGE?
AMBER
DPM OFF MODE (NO H and/or V SYNC)
GREEN
CHECK D712 ANODE (-160V)?
NO
TROUBLE IN D712
YES
CHECK G1 VOLTAGE? (-45 ~ -55V)
NO
TROUBLE IN Q704
YES
CHECK CDT HEAT VOLTAGE? (6.3V)
NO
TROUBLE IN 6.3V LINE
YES
TROUBLE IN CDT
4. NO HORIZONTAL DEFLECTION
NO H-DEFLECTION (ONE VERTICAL LINE)
CHECK Q706?
NO
TROUBLE IN Q706
YES
CHECK B+ VOLTAGE (49V)?
NO
TROUBLE IN 50V LINE
YES
CHECK T701(FBT) PIN 2 (31KHZ, 60V)?
NO
TROUBLE IN Q719, Q720, D710
YES
CHECK Q705 COLLECTOR WAVEFORM?
NO
TROUBLE IN Q705
0V T
YES
TROUBLE IN T701, P701
5. TROUBLE IN H-LINEARITY
UNBALANCED OF H-LIN.
CHECK IC401 PIN 22, 24 ?
NO
TROUBLE IN IC401 (MICOM)
YES
CHECK Q711, Q713 Q714, Q716?
NO
TROUBLE IN Q711 ~ Q716
YES
CHECK L703, D719?
NO
TROUBLE IN L703, D719
YES
Cs SIGNAL TABLE
TROUBLE IN C722, C723, C729
HORIZONTAL FREQUENCY(fH)
C1 L H L H
C2 -
C3 L L H H
30K 36K 40K 50K
~ ~ ~ ~
35.9K 39.9K 49.9K 53.9K
6. NO VERTICAL DEFLECTION
NO V-DEFLECTION (ONE HORIZONTAL LINE)
CHECK IC601 PIN 3 (15V)?
NO
TROUBLE IN R603 15V LINE
YES
CHECK IC601 PIN 7 (40V)?
NO
TROUBLE IN HIGH-VOLTAGE OUT CIRCUIT(FBT), D721, R606
YES
CHECK IC701 PIN 12, 13?
NO
TROUBLE IN IC701
3V
YES
TROUBLE IN IC601, V-CIRCUIT
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 (H-FBP)
Pin 5
YES
CHECK IC301 PIN 12 WAVEFORM ?
H+V 5V
NO
TROUBLE IN IC302, IC301
YES
CHECK IC301 PIN 13, 14, 15 ?
H+V 5V
NO
TROUBLE IN IC301, IC302
YES
TROUBLE IN OSD PERIPHERAL CIRCUIT
8. TROUBLE IN DPM
OFF MODE FAILURE
(NO OFF MODE.)
CHECK IC401 (MICOM) PIN 1, 42 (H/V INPUT) SIGNAL?
NO
INPUT H/V SYNC SIGNAL
CHECK PC, (PC IS NOT GOING INTO DPM OFF MODE)
YES
H/V SYNC
CHECK IC401 PIN 6 WAVEFORM?
5V
NO
TROUBLE IN X401
YES
24MHz
CHECK IC401 (MICOM) PIN 4? SEE DPM TABLE YES
NO
(DPMF: 0V)
TROUBLE IN IC401 (MICOM)
CHECK B+ LINE (6.3V,15V, 80V) ?
NO
TROUBLE IN Q903, PC902, IC904
YES
TROUBLE IN PC Mode Item
DPM TABLE DPMF H L LED GREEN AMBER
NORMAL OFF
9. NO DEGAUSSING
NO DEGAUSSING
(DEGAUSS ON THE OSD MENU MUST BE PRESSED.)
CHECK IC401 PIN 31 (0V)?
NO
TROUBLE IN IC401 (MICOM)
YES
CHECK Q953 COLLECTOR VOLTAGE? DC 15V YES
NO
TROUBLE IN Q953
CHECK P902 ?
NO
TROUBLE IN P902
YES
CHECK RL901?
NO
TROUBLE IN RL901
YES TROUBLE IN TH901, DEGAUSSING COIL