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ACER H233H
5. Troubleshooting (continued)
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5.9Checking the interface circuit of sync signal
5.9.1Checking the control circuit of horizontal sync pulse
Check the horizontal sync signal on P302 pin13 TTL
level.
NG
OK
Failure Point
Video cable is failure.
Check the horizontal sync signal on I308 pin 22 TTL
level.
NG
OK
Failure Point
Proceed "Checking the resolution change IC movement" section.
Failure Point
1)Printed wire broke between P302 pin13 and I308 pin22.
2)FB304 , R405 is open.
3)D307 ,R319 or C322 is short.
5.9.2 Checking the control circuit of vertical sync pulse
Check the vertical sync signal on P302 pin14 TTL level.
NG
OK
Failure Point
Video cable is failure.
Check the horizontal sync signal on I308 pin21 TTL
level.
NG
OK
Failure Point
Proceed "Checking the resolution change IC movement" section.
Failure Point
1)Printed wire broke between P302 pin14 and I308 pin21.
2)FB305 or R331 is open.
3)D310,R318 or C313 is short.