IBM eServer 342 xSeries, User Reference Manual

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Chapter 5. Installing Options
31
System board switches and jumpers
The following illustration identifies the switches and jumpers on the system board.
Note: The illustrations in this document might differ slightly from your hardware.
Note: Any jumper blocks on the system board that are not shown in the illustration
are reserved.
System board jumper blocks
For typical operation of the system, no jumpers should be installed on any of the
jumper blocks. See “Recovering BIOS code” on page 106 for information about the
boot block jumper.
Flash boot block recovery jumper
If the BIOS has become damaged, 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. See
“Recovering BIOS code” on page 106 for information about the boot block jumper.
System board switch block
The switch block contains microswitches 1 through 8. As shown in this illustration,
switch 1 is at the top of the switch block and switch 8 is at the bottom. The Off position
for each switch is on the side nearer the microprocessor socket.
1 2 3 4 5 6 7 8
SW1
Flash boot block
recovery jumper (J16)
System board
Switch block (SW1)
ON