Acer A221HQV Acer A221HQV LCD Monitor Service Guide - Page 42

40 ACER A211H/A221HQ Go to contents page 5. Troubleshooting (continued) 5.2.5 Abnormal OSD display adjust problem: Check the input level whether was changed when pressed function keys on the CN304 pin 1, 2. (Normal is 3.3V, when push button, genertaed different voltage. Pin 1, 2 is 0.69V or 1.65V or 2.11V) Failure Point NG 1) Function key wire disconnection. 2) Function key wire is failure. 3) Function key board is failure. OK Check the input level whether was changed when pressed function keys on the I310 pin 52, 53. (Normal is 3.3V, when push button, genertaed 0.69V or 1.65V or 2.11V) Failure Point 1) Printed wire broke between CN304 pin 1, I310 pin 52. NG 2) Printed wire broke between CN304 pin 2, I310 pin 53. 3) C363 or C364 is short. 4) R380 or R381 is short or open. 4) R382 or R383 is open. OK Failure Point I310 is failure