Acer A221HQV Acer A221HQV LCD Monitor Service Guide - Page 30

28 ACER A211H/A221HQ Go to contents page 5. Troubleshooting (continued) 5.1.6 Abnormal plug and play operation( for VGA): Confirm the host computer supplies DDC2B mode. OK NG Failure Point The host machine is not communicatiog in DDC2B mode. Check the voltage on P302 pin 9 that is power DC 5 V. OK NG Failure Point TheVideo cable is failure. Check the signal on P302 pin12, 15 that is serial data / clock signal. OK NG Failure Point The Video cable is failure. Check the output signal of serial data / clock on I308 pin 59, 58. OK NG Failure Point 1) Printed wire broke among I308 pin 58, 59, R320, R321 and P302 pin 12,15 2) I308 maybe failure. 3) R434 ,R429 is open. 4) D306 or D308 or C320 or C321 is shorted. Failure Point I308 is failure.