IBM xSeries 235, Maintenance & Troubleshooting

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Recovering the BIOS code
If the BIOS code has become damaged, such as from a power failure during a flash
update, you can recover the BIOS code using a BIOS flash diskette.
Note: You can obtain a BIOS flash diskette from one of the following sources:
v Use the ServerGuide program to make a BIOS flash diskette.
v
Download a BIOS flash diskette from the World Wide Web. Go to
http://www.ibm.com/pc/support/, click
IBM Server Support , and make the
selections for your server.
v Contact your IBM service representative.
Complete the following steps to recover the BIOS code:
1. Turn off the server and disconnect all power cords and external cables; then,
remove the server cover (see “Removing the left-side cover” on page 51).
2. Locate the boot block recovery jumper (J28) on the system board. See
“System-board switches and jumpers” on page 47 for jumper location.
3. Remove the jumper from pins 1 and 2 of boot block recovery jumper and place
it on pins 2 and 3 of the boot block recovery jumper to enable BIOS recovery
mode.
4. Insert the BIOS flash diskette into the diskette drive.
5. Reconnect all power cords; then, reinstall the server cover.
6. Restart the server. The system begins the power-on self-test (POST).
7. Select 1 - Update POST/BIOS from the menu that contains various flash
(update) options.
8. When prompted as to whether you want to save the current code to a diskette,
press N.
9. When prompted to choose a language, select a language (from 0 to 7) and
press Enter to accept your choice.
10. Do not restart your server at this time.
11. Remove the BIOS flash diskette from the diskette drive.
12. Turn off the server and disconnect all power cords; then, remove the server
cover.
13. Remove the jumper from pins 2 and 3 of boot block recovery jumper (J28) and
place it on pins 1 and 2 of the boot block recovery jumper to return to normal
startup mode.
14. Reconnect all external cables and power cords and turn on the peripheral
devices; then, reinstall the server cover and restart the server. The system
starts.
Power checkout
Power problems can be difficult to solve. For example, a short circuit can exist
anywhere on any of the power distribution buses. Usually a short circuit will cause
the power subsystem to shut down because of an overcurrent condition.
A general procedure for troubleshooting power problems is as follows:
1. Turn off the server and disconnect all ac power cords.
2. Check for loose cables in the power subsystem. Also check for short circuits, for
example, if there is a loose screw causing a short circuit on a circuit board.
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xSeries 235 Type 8671: Hardware Maintenance Manual and Troubleshooting Guide