6-12
7. Checking the Sync Signal Interface Circuit
7.1 Checking the Horizontal Sync Pulse Control Circuit
7.2 Checking the Vertical Sync Pulse Control Circuit
OK
NG
Check the horizontal sync signal on I315 pin L2 TTL level.
Process "Checking the IC Resolution Change Movement" section.
Failure point
1) Video cable may have failed.
2) Printed wire broke between P304 pin 13 and I315 pin L2.
3) FB305, R329 open.
4) R330, C352 short.
OK
NG
Check the vertical sync signal on I315 pin K1 TTL level.
Process "Checking the IC Resolution Change Movement" section.
Failure point
1) Video cable may have failed.
2) Printed wire broke between P304 pin 14 and I315 pin k1.
3) R328, FB304 open.
4) R331, C353 short.