Acer Aspire 2420, Service Manual

Page: 126 / 170

116 Chapter 4
Undetermined Problems
The 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 “Power
System Check” on page 99.):
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:
K Non-Acer devices
K Printer, mouse, and other external devices
K Battery pack
K Hard disk drive
K DIMM
K CD-ROM/Diskette drive Module
K PC Cards
4. 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:
K System board
K LCD assembly