Philips V40 109B6 - Page 77

Repair Flow Chart
109B6 CRT
77
B. Video
Repair Flow
Rough check for R, G, B
1. Video input=0.7V
2. 7331 Video output=2.5v
3. 7701 Video output>35V
1. Symptom:
(with white pattern)
no picture
green LED on
Check hearter
=+6.3V
Check
EHT=26KV
+/-0.2V
Check VG2>350V
OK
Check
VG1<-150V
OK
NO
Check
R, G, B output
30<2725<80
30<2733<80
30<2753<80
2. Symptom:
no video (or dim)
only raster with/without retrace line
green LED on
Check 7301 Pin24
2V<ABL<5V
Check 7301
Pin 6.8.10
input swing
Check 7701
Pin 6.7.9
input swing
Check 7701
Pin 1.2.3
output swing
OK
Replace 7701
Replace IF
cable
NO
Check 7301
Pin11 HFLB
OK
Replace 7301
NO
Check Vg1
Vg1=0V
Turn down Vg2
Check cathode
+83V
OK
OK
3. Symptom:
no OSD or
OSD out of Sync.
Check 7301
pin 2.3.4 input
Check HUNLOCK
7501 Pin17
Check Blanking
7501 pin16
OK
Check DC Restoration
7722,7732,7752,
77
21,7731,7751
Check 7301
pin5 CLBL
Check 7501 pin16
Ok
No
Check 7304 pin10
VFLB
Check 7304
pin2 VCO
Pin3 RP
NO
CHECK 7301
PIN1
Check 7304
pin5 HFLB
Check 7304
pin12
Check 7304
pin7.8(IIC)
REPLACE 7304
REPLACE7301
NO
NO
OK
OK
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