Acer A221HQV Acer A221HQV LCD Monitor Service Guide - Page 31

5. Troubleshooting (continued) ACER A211H/A221HQ 29 Go to contents page 5.1.6 Abnormal plug and play operation (For DVI and the same for HDMI): Confirm the host computersupplies DDC2B mode. OK NG Check the voltage on P303 pin14 that is power DC 5 V. Failure Point The host machine is not communicatiog in DDC2B mode. OK NG Failure Point The Video cable is failure. Check the voltage on P303 pin 16 that is 4.5V. OK NG Check the voltage on P303 pin 7, 6 that is serial data / clock signal. Failure Point Printed wire broke between P303 pin 14 and pin 16. OK NG Failure Point The Video cable is failure. Check the output signal of serial data / clock on I308 pin 122,121 OK NG Failure Point 1) Printed wire broke between I308 pin122, 121,R344, R345 and P303 pin7,6 2) I308 maybe failure. 3) R410, R414 is open. 4) D320 or D321 or C339 or C342 is shorted. Failure Point I308 is failure.