Acer 721TX Service Guide - Page 102

Symptom / Error In DOS or Windows multimedia programs, no sound comes from the computer. External display does not work correctly. USB does not work correctly. Print problems Serial or parallel port device problems FRU / Action in Sequence 1. Speaker 2. System board System board System board 1. Run printer self-test. 2. Printer driver 3. Printer cable 4. System board 1. Device driver 2. Device cable 3. Device 4. System board 94 Troubleshooting