Samsung sf150t Service Manual page 19

Troubleshooting
6-2-1 No + 5 V
Start
Y
DC 6 V
N
Check PCB Pattern
6-2-2 No -12 V
Start
Y
-15 VDC
N
Check PCB Pattern
6-4
N
output shorted ?
Y
Remove short
Y
Check U2 ?
N
Replace U2
N
output shorted ?
Y
Remove short
Y
U1 Output ?
N
Replace U1
D4 Open or
N
Shorted ?
Y
Replace D4
Check CON 1
N
D5 Open or
Shorted ?
Y
Replace D5
Check CON1
Check
U2 Input voltage
End
Check
U1 Input voltage
End
SF150T