IBM 3745 Series, Installation And Maintenance Manual

Page: 107 / 270

Undetermined Problems
If an undetermined problem exists, check the power supply voltages (see
“Power-Supply” on page 3-21). If the voltages are correct, return here and
continue with the following steps.
1. Power-off the computer.
2. Remove or disconnect the following, if installed, one at a time:
a. Non-IBM devices
b. External devices (modem, printer, or mouse)
c. Any adapters
d. Memory modules
Before removing or replacing memory modules, see “System Board
Memory” on page 3-38.
e. Extended video memory
f. External Cache
g. External Cache RAM
h. Hard drive
i. Diskette drive
3. Power-on the computer to re-test the system.
4. Repeat steps 1 through 3 until you find the failing device or adapter.
If all devices and adapters have been removed, and the problem continues, replace
the system board (see “Before Replacing a System Board”).
Before Replacing a System Board
Notes
1. The BIOS and Vital Product Data (VPD) for the service processor must be
installed on the new system board after it is installed in the service
processor. To do this, you must run the Flash Update Diskette. See
“Flash (BIOS/VPD) Update Procedure” on page 3-34.
2. Always ensure the latest level of BIOS is installed on the computer. A
down level BIOS may cause false errors and unnecessary replacement of
the system board.
3. The processor is a separate FRU from the system board and is not included
with the system board FRU. If you are instructed to replace the system
board, do the following.
4. Remove the processor from the old system board and install it on the new
system board.
5. Remove any of the following installed options on the old system board, and
install them on the new system board.
¹
Memory modules
6. Ensure that the new system board jumper settings match the old system
board jumper settings.
7. If the new system board does not correct the problem, reinstall the options
on the old system board, reinstall the old system board, then replace the
processor.
Chapter 3. Service Processor Troubleshooting
3-23