Acer AL1702 AL1702 Service Guide - Page 19

5. Abnormal OSM display adjust problem AL1702 Check the input TTL level whether was changed when pressed function keys on the P308 pin3, 4, 5, 6. (normal is high level, when push buttom, generated low level plus) NG OK Failure Point 1) Function key wire disconnection. 2) Function key wire is failure. 3) Function key board is failure. Check the input TTL level whether was changed when pressed function keys on the I307 pin1, 2, 41, 42. (normal is high level, when push buttom, generated low level plus) NG OK Failure Point I307 is failure. Failure Point 1) Printed wire broke between P308 pin3 and I307 pin41. 2) Printed wire broke between P308 pin4 and I307 pin2. 3) Printed wire broke between P308 pin5 and I307 pin1. 4) Printed wire broke between P308 pin6 and I307 pin42. 5) C404, C405, C406, C407 is short. 6) R367, R368, R369, R370 is short or open. Page 17