Service manual

Page 19
AL1702
Check the horizontal sync signal on P302 pin3 TTL
level.
OK
NG
Check the horizontal sync signal on I305 pin37 TTL
level.
OK
NG
Failure Point
1) Printed wire broke between P302 pin3 and
I305 pin37.
2) FB313, R329 open.
3) R331, C346 short.
Failure Point
Process "Checking the resolution change IC
movement" section.
Failure Point
Video cable is failure.
Check the horizontal sync signal on P302 pin2 TTL
level.
OK
NG
Failure Point
Video cable is failure.
Check the horizontal sync signal on I305 pin36 TTL
level.
OK
NG
Failure Point
1) Printed wire broke between P302 pin3 and
I305 pin36.
2) FB312, R328 open.
3) R330, C345 short.
Failure Point
Process "Checking the resolution change IC
movement" section.
7. Checking the interface circuit of sync signal
7.1 Checking the control circuit of horizontal sync pluse
7.2 Checking the control circuit of vertical sync pluse