Acer Extensa 7620 TravelMate 7720 / 7320 and Extensa 7620 Service Guide - Page 133

Intermittent Problems Intermittent system hang problems can be caused by a variety of reasons that have nothing to do with a hardware defect, such as: cosmic radiation, electrostatic discharge, or software errors. FRU replacement should be considered only when a recurring problem exists. When analyzing an intermittent problem, do the following: 1. Run the advanced diagnostic test for the system board in loop mode at least 10 times. 2. If no error is detected, do not replace any FRU. 3. If any error is detected, replace the FRU. Rerun the test to verify that there are no more errors. Chapter 4 123