Acer AL1702 AL1702 Service Guide - Page 21

7. Checking the interface circuit of sync signal 7.1 Checking the control circuit of horizontal sync pluse AL1702 Check the horizontal sync signal on P302 pin3 TTL level. NG OK Failure Point Video cable is failure. Check the horizontal sync signal on I305 pin37 TTL level. NG OK Failure Point Process "Checking the resolution change IC movement" section. Failure Point 1) Printed wire broke between P302 pin3 and I305 pin37. 2) FB313, R329 open. 3) R331, C346 short. 7.2 Checking the control circuit of vertical sync pluse Check the horizontal sync signal on P302 pin2 TTL level. NG OK Failure Point Video cable is failure. Check the horizontal sync signal on I305 pin36 TTL level. NG OK Failure Point Process "Checking the resolution change IC movement" section. Failure Point 1) Printed wire broke between P302 pin3 and I305 pin36. 2) FB312, R328 open. 3) R330, C345 short. Page 19