Acer RA19WAANU Service Manual page 29

ACER X193HQ
28
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5.9 Checking the interface circuit of sync signal
5.9.1 Checking the control circuit of horizontal sync pluse
5.9.2 Checking the control circuit of vertical sync pluse
5. Troubleshooting (continued)
Check the horizontal sync signal on P302 pin13 TTL
level.
OK
Check the horizontal sync signal on I308 pin9 TTL
level.
OK
Failure Point
Process "Checking the resolution change IC movement"
section.
Check the vertical sync signal on P302 pin14 TTL level.
OK
Check the horizontal sync signal on I308 pin8 TTL
level.
OK
Failure Point
Process "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
I308 pin9.
2) FB304 , R309 is open.
3) D307 ,R319 or C322 is short.
NG
Failure Point
Video cable is failure.
Failure Point
NG
1) Printed wire broke between P302 pin14 and
I308 pin8.
2) FB305 or R308 is open.
3) D310,R318 or C313 is short.