Acer A221HQV Acer A221HQV LCD Monitor Service Guide - Page 29

5. Troubleshooting (continued) 5.1.5 Abnormal OSD display adjust problem: ACER A211H/A221HQ 27 Go to contents page Check the input TTL level whether is changed when pressed function keys on the P310 pin 5, 6 (normal is high level, when push button, generated low level) OK NG Failure Point 1) Function key wire disconnection. 2) Function key wire is failure. 3) Function key board is failure. Check the input TTL level of I308 pin 50, 51 whether is changed when pressed function keys. OK NG Failure Point 1) Printed wire broke among P310 pin5, R503 and I308 pin50 2) Printed wire broke among P310 pin6 ,R504 and I308 pin51 Failure Point I308 is failure.