5. Troubleshooting (continued)
5.7 Checking the interface circuit of sync signal
5.7.1 Checking the control circuit of horizontal sync pulse
5.7.2 Checking the control circuit of vertical sync pulse
Check the horizontal
sync signal on I314 pin46
TTL level
OK
Failure Point
1. Video cable is defected.
2. Printed wire is broken between P304 pin13 and I314 pin46.
3. FB305, R364, R363 is open.
4. R371, C336, D305 is short.
5. I311 is defected.
Proceed to “5.8 Checking the
resolution change IC movement”
section
NG
Check the vertical sync
signal on I314 pin47 TTL level
OK
Failure Point
1. Video cable is defected.
2. Printed wire is broken between P314 pin14 and I314 pin47.
3. FB306, R368, R369 is open or more than one component.
4. R370, C335, D303 is short.
5. I311 is defected.
Proceed to “5.8 Checking the resolution
change IC movement” section
NG
Go to cover page
26
ACER P243W