Philips V30 - Manual (Page 74)

Repair Flow Chart (Continued)
B.Video
Repair Flow
check 7331
Pin24 HFLB
1.Sympton :
(with white pattern)
no picture
green LED on check
EHT=25KV
rough check for R,G, B
1. video input= 0.7V
2. 7331video output =2.5V
3. 7701 video output > 35Vpp
check DC restoration
7722,7732,7752
7721,7731,7751
check 7331 pin22
2V< ABL < 5V
check 7331
pin 7,6,5
input swing
check 7701
pin 1, 2, 4
input swing
Ok
replace 7701
Ok
replace IF
cable
No
replace 7331
check
VG1 < -150V
Ok
No
check blanking
7501 pin3
check heater
= + 6.3V
Ok
check Xray prot.
7501 pin25
No
check
R,G,B output
30<2722<80
30<2723<80
30<2724<80
Ok
2.Sympton :
no video (or dim),
only raster with/without retrace line
green LED on check Vg1
Vg1 = -30V
check cathod
+83V,
Ok
check blanking
7501 pin3
No turn down Vg2
check 7701
pin 9,10,11
output swing
3. Sympton :
no OSD or
OSD out of sync.
H.V.check 7331
check
VG2 > 450V
Ok
9
Go to cover page
V30 107T5 74
Ok