Acer AL2002 AL2002 Service Guide - Page 45

Appendix 4: Troubleshooting Abnormal plug and play operation for VGA ACER AL2002W 9 Go to cover page Confirm the host computer supplies DDC2 mode. NG Failure Point: The host computer is not communicating in DDC2 mode. OK Check the voltage on P302 pin10 that is power DC 5V. NG Failure Point: The VGA video cable is defected. OK Check the voltage on I304 pin8 that is power DC 5V. Failure Point: NG 1. Printed wire is broken between P302 pin9 and I304 pin8 2. D307 or D308 is damaged. OK Check the voltage on P302 pin12, pin15 that are serial data and clock signal. Failure Point: NG The VGA video cable is damaged. If I304 pin5, pin6 LOW, the I304 may be failure. OK Check the output signal of serial data and clock signal I304 pin5 and pin6 NG Failure Point: I304 is defected. OK Failure Point: 1. R328, R329, R326, R327 is open. 2. D309, D310 is short. 3. C331, C332 is short.