Checking The Sync Signal Interface Circuit; Checking The Horizontal Sync Pulse Control Circuit - NEC AccuSync LCD51VM Series Service Manual

6. Checking the Sync Signal Interface Circuit

6.1 Checking the Horizontal Sync Pulse Control Circuit

Check the horizontal sync signal on U402 pin 1 at
TTL level.
NG
OK
Check the horizontal sync signal on U405 pin 101 is
at TTL level.
NG
OK
Procees Section 7 "Checking the Scaling IC
Operation".
1) No separate sync or sync output by Sync on
Green. (Confirm the host, output the sync
signal.)
2) Video cable may have failed.
3) Printed wire broke between P401 pin 13 and
U402 pin 1.
4) B401 or R415. open.
5) U402 failure.
Failure point
1) U402 failure.
2) R479 open.
6-8
Failure point