Acer AL2002 AL2002 Service Guide - Page 47

Appendix 4: Troubleshooting Checking the control circuit of horizontal sync pulse for DVI-D Check the horizontal sync signal on P302 pin13 TTL level Failure Point: NG VGA Video cable is damaged. OK Check the horizontal sync signal on I306 pin89 TTL level Failure Point: 1. Printed wire is open between P301 pin13 and I306 NG pin89. 2. FB311 and R321 may be open. 3. R324 and C328 may be short. 4. D306 is short. OK Proceed 'Checking the resolution change IC movement' section Checking the control circuit of vertical sync pulse for VGA Check the vertical sync signal on P302 pin14 TTL level Failure Point: NG VGA video cables is failure. OK Check the vertical sync signal on I306 pin90 TTL level Failure Point: 1. Printed wire is open between P302 pin14 and I306 NG pin90. 2. FB312 and R322 may be open. 3. R323 and C327 may be short. 4. D305 is short. OK Proceed 'Checking the resolution change IC movement' section Checking the TMDS signal input for DVI-D ACER AL2002W 11 Go to cover page Check the TMDS signal P303 pin1, pin2, pin9, pin10, pin17, pin18, pin23, pin24 OK Check the TMDS signal I306 pin72, pin73, pin75, pin76, pin80, pin81, pin83, pin84 Failure Point: NG DVI-I Video cable is damaged. Failure Point: NG 1. Printed wire is open between P303 and I306 pin89. 2. R332~R335 R338~R341 may be open. OK Proceed 'Checking the resolution change IC movement' section