IBM A40 TYPE 6840, Hardware Maintenance Manual

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Message/Symptom FRU/Action
Some or all keys on the keyboard do not
work
1. Keyboard
2. Keyboard Cable
3.
System Board
Undetermined problems
Check the power supply voltages (see “Power supply” on page 33). If the voltages
are correct, return here and continue with the following steps.
1. Power-off the computer.
2.
Remove or disconnect the following components (if installed) one at a time.
a. Non-IBM devices
b.
External devices (modem, printer, or mouse)
c. Any adapters
d. Riser card
e. Memory modules
Before removing or replacing memory modules, see “System board
memory” on page 30.
f. Extended video memory
g.
External Cache
h. External Cache RAM
i.
Hard disk drive
j. 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 “Replacing a system board” on page 31).
Chapter 6. Symptom-to-FRU Index
75