Undetermined Problems - Lenovo ThinkCentre 7244 Hardware Maintenance Manual

Message/Symptom
Serial or parallel port device failure (system board port)
Serial or parallel port device failure (adapter port)
Some or all keys on the keyboard do not work

Undetermined problems

If you encounter undetermined problems, do the following:
1. Turn off the computer and the power.
2. Remove or disconnect the following components (if installed) one at a time.
a. External devices (modem, printer, or mouse)
b. Any adapter cards
c. Memory modules
d. Extended video memory
e. External Cache
f. External Cache RAM
g. Hard disk drive
h. Diskette drive
3. Turn on the power and the computer to re-test the system.
4. Repeat steps 1 through 3 until you find the failing device or adapter cards.
If all devices and adapter cards have been removed, and the problem continues, replace the system board.
See "Replacing the system board" on page 84 or "Replacing the system board" on page 121.
FRU/Action
1. External Device Self-Test OK?
2. External Device
3. Cable
4. System Board
1. External Device Self-Test OK?
2. External Device
3. Cable
4. Alternate Adapter
5. System Board
1. Keyboard
2. Keyboard Cable
3. System Board
Chapter 7
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Symptom-to-FRU index
69