6-9
6. Checking the interface circuit of sync signal
6.1 Checking the control circuit of horizontal sync pulse
Check the horizontal sync signal on IC203 pin3 at
TTL level.
NG
OK
Failure point
1) No separate sync or composite sync
output by host. (Confirm the host,
output the sync signal.)
2) Video cable may have failed.
3) Printed wire broke between J201 pin
13 and IC203 pin3.
4) L208 or R211. open
5) IC203 failure.
Procees section 7 “Checking the resolution change
IC movement”
NG
OK
Failure point
IC401 failure
Check the hovizuntal sync signal on IC401 pin141
a TTL level.