105S2 CM23 GSIII
Repair Flow Chart
B.Video
Repair Flow
check 7301
pin11 HFLB
1.Sympton :
( input a white pattern signal )
no picture
green LED on
check
EHT=25KV
check R,G, B input / output
1. video input= 0.7V
2. 7301video output =2.5V
3. 7701 video output= 35V swing
check 7301
pin5 CLBL
check 7301
pin24
2V< ABL < 5V
check 7301
pin 6,8,10
input swing
check 7701
pin 8,9,11
input swing
Ok
replace 7701
Ok
check
IF cable
No
replace 7301
check
VG1< -100V
Y
N
check
7501 pin17
Y
check
heater = 6V
Ok
check Xay-prot.
7501 pin2
N
check R,G,B output
30<2725<80
30<2733<80
30<2753<80
N
2.Sympton :
no video ( or dim )
only raster with green LED
check VG1
VG1 <-100V
check +80V
supply
Ok
check blanking
7501 pin16
N
turn high
VG2
check 7701
pin 1,3,5
output swing
check 7501
pin16
check CRT
No
Ok
check DC restoration
7722,7732,7752
7721,7731,7751
check
VG2 > 400V
Ok
N
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