Acer AC100, Service Manual

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78 Chapter 6
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If the system has not crashed or if you want to revert BIOS to previous settings:
During POST, press < Ctrl > + < Home > during POST. This action will flash the BIOS from the USB
storage device to the system and reboot automatically after the flash update is completed.
4. Remove the BIOS Recovery disk.
Clearing CMOS
To clear the BIOS configuration you need to short the JP3 Clear CMOS jumper on the mainboard.
1. Turn off the computer and all attached devices.
2. Remove the system cover. See “Removing the System Cover” on page 30.
3. Locate the JP3 Clear CMOS jumper on the mainboard.
4. Remove the jumper from the default position.
5. Replace the jumper to connect the 2nd and 3rd pins.
6. Access the BIOS Setup Utility by connecting a debug card, keyboard, and a monitor to the system.
Perform steps 3 and 7 through 10 of the “Entering the BIOS Setup Utility” on page 10.
7. Press < F9 > to load the system default values.
8. Press < F10 > to save the changes made and close the Setup Utility.
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.
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 74)
Follow procedures below to isolate the failing FRU. Do not isolate non-defective FRU.
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:
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Non-Acer devices
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Printer, mouse, and other external devices
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Hard disk drive
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DIMM
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CD/DVD-ROM drive
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Adapter cards
4. Power on the computer.
5. Determine if the problem has been resolved.
6. If the problem does not recur, reconnect the removed devices one at a time until you find the failed FRU.
7. If the problem persists, replace the FRU one at a time. Do not replace a non-defective FRU.