Acer NA23WABAS Service Manual page 49

48
ACER V233H
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5.9 Checking the interface circuit of sync signal
5.9.1 Checking the control circuit of horizontal sync pulse
5.9.2 Checking the control circuit of vertical sync pulse
5. Troubleshooting (continued)
Check the horizontal sync signal on P303 pin13 TTL
level.
OK
Check the horizontal sync signal on I312 pin36 TTL
level.
OK
Failure Point
Proceed "Checking the resolution change IC movement"
section.
Check the vertical sync signal on P303 pin14 TTL level.
OK
Check the horizontal sync signal on I312 pin37 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 P303 pin13 and
I312 pin36.
2) FB308 , R349 is open.
3) D320 ,R353 or C331 is short.
NG
Failure Point
Video cable is failure.
Failure Point
NG
1) Printed wire broke between P303 pin14 and
I312 pin37.
2) FB309 or R351 is open.
3) D319,R352 or C330 is short.