Acer NA23WABAS Service Manual page 37

36
ACER V233H
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5.9 Checking the interface circuit of sync signa
5.9.1 Checking the control circuit of horizontal sync pulse
5.7.2 Checking the control circuit of vertical sync pulse
5. Troubleshooting (continued)
Check the horizontal sync signal on P302 pin13 TTL
level.
OK
Check the horizontal sync signal on I307 pin41 TTL
level.
OK
Failure Point
Proceed "Checking the resolution change IC movement"
section.
Check the vertical sync signal on P302 pin14 TTL level.
OK
Check the horizontal sync signal on I307 pin42 TTL
level.
OK
Failure Point
Proceed "Checking the resolution change IC movement"
section.
NG
Failure Point
Video cable is failure.
Failure Point
NG
1) Printed wire broke between P302 pin13 and
I307 pin41.
2) R321 is open.
3) D307 ,R324 or C327 is short.
NG
Failure Point
Video cable is failure.
Failure Point
NG
1) Printed wire broke between P302 pin14 and
I307 pin42.
2) R322 is open.
3) D306,R323 or C326 is short.