Acer A221HQV Acer A221HQV LCD Monitor Service Guide - Page 44

42 ACER A211H/A221HQ Go to contents page 5. Troubleshooting (continued) 5.1.6.2 Abnormal plug and play operation for DVI Confirm the host computer supplies DDC/CI mode. Failure Point NG The host machine is not communicated in DDC/ CI mode. OK Check the voltage on CN303 pin 14, that is DC 5 V. Failure Point NG The DVI video cable is failure. OK Check the voltage on I305 pin 8, that is DC 5 V. OK Failure Point NG 1) Printed wire broke between I305 pin 8, D311 and CN303 pin 14. 2) D311 is failure. Check the signals if is high level on CN303 pin 7, 6, that is I2C data / clk signal. Failure Point NG The DVI video cable is failure. OK Check the output signal of I2C data / clk on I305 pin 5, 6. Failure Point NG I305 is failure. OK Failure Point 1) Printed wire broke between I310 pin 123, 124, I305 pin 5, 6 and CN303 pin 7, 6. 2) I310 maybe failure. 3) R339 or R340 is open. 4) C338, C339, R337, R338 is short.