Undetermined Problems - Lenovo 821532U - ThinkCentre M52 - 8215 Hardware Maintenance Manual

Undetermined problems

Check the power supply voltages (see "Power Supply Errors" on page 57). 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.
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.
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Hardware Maintenance Manual
Message/Symptom
Some or all keys on the keyboard do not
work
a. External devices (modem, printer, or mouse)
b. Any adapters
c. Riser card
d. Memory modules
e. Extended video memory
f. External Cache
g. External Cache RAM
h. Hard disk drive
i. Diskette drive
FRU/Action
1. Keyboard
2. Keyboard Cable
3. System Board