1.Power off the server and disconnect the AC cord(s).
2.Check for loose cables in the power subsystem. Also check for short circuits, for instance if there is a loose screw causing a short circuit on a circuit board.
3.Remove adapters and disconnect the cables and power connectors to all internal and external devices until server is at minimum configuration required for power on (see "Minimum operating requirements" on page 100).
4.Reconnect the AC cord and power on the server. If the server powers up successfully, replace adapters and devices one at a time until the problem is isolated. If server does not power up from minimal configuration, replace FRUs of minimal configuration one at a time until the problem is isolated.
To use this method it is important to know the minimum configuration required for a server to power up (see page 100).
Recovering BIOS
If the BIOS has become corrupted, such as from a power failure during a flash update, you can recover the BIOS using the boot block jumper and a BIOS flash diskette. The boot block jumper selects which of two BIOS images to use. In the normal position, the jumper will be installed on pins 2 and 3. In the alternate block position, the jumper will be installed on pins 1 and 2.
Note: You can obtain a BIOS flash diskette from one of the following sources:
•Use the ServerGuide program to make a BIOS flash diskette.
•Download files to make a BIOS flash diskette from the World Wide Web. Go to http://www.ibm.com/support/ select IBM System Support, and then make the selections for your system.
Do the following to recover the BIOS:
1.Turn off the server and peripheral devices and disconnect all external cables and power cords; then, remove the side cover, see “Removing the side cover” on page 40.
2.Locate jumper JROM1 on the system board.
1
2
3
CMOS jumper (JBAT1)
3
2
1
Boot block jumper
14Hardware Maintenance Manual: xSeries 200
