182 Chapter 4Undetermined ProblemsThe diagnostic problems does not identify which adapter or device failed, which installed devices are incorrect,whether a short circuit is suspected, or whether the system is inoperative.Follow these procedures to isolate the failing FRU (do not isolate non-defective FRU).NOTE: Verify that all attached devices are supported by the computer.NOTE: Verify that the power supply being used at the time of the failure is operating correctly. (See “PowerSystem Check” on page 167).1. Power-off the computer.2. Visually check them for damage. If any problems are found, replace the FRU.3. Remove or disconnect all of the following devices:z Non-Acer devicesz Printer, mouse, and other external devicesz Battery packz Hard disk drivez DIMMz CD-ROM/Diskette drive Modulez PC Cards4. Power-on the computer.5. Determine if the problem has changed.6. If the problem does not recur, reconnect the removed devices one at a time until you find the failing FRU.7. If the problem remains, replace the following FRU one at a time. Do not replace a non-defective FRU:z System boardz LCD assembly
