Message/Symptom
FRU/Action
Serial or parallel connector device failure (adapter
connector)
1. External Device Self-Test OK?
2. External Device
3. Cable
4. Alternate Adapter
5. System Board
Some or all keys on the keyboard do not work
1. Keyboard
2. Keyboard Cable
3. System Board
Undetermined problems
This section provides instructions on how to find out the failing devices or adapters.
1. Turn off the computer.
2. Remove or disconnect the following components (if installed) one at a time.
a. External devices (modem, printer, or mouse)
b. Any adapters
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 computer to retest 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
Chapter 5 “Hardware removal and installation” on page 41.
Diagnostics
Use diagnostic solutions to test hardware components and report operating-system-controlled settings that
interfere with the correct operation of your computer.
Basic procedure for resolving computer problems
Prerequisite
Before you start, read Chapter 1 “Important safety information” on page 1 and print the following
instructions.
1. Check that:
a. The cables for all connected devices are connected correctly and securely.
b. All components have been reassembled correctly.
c. All connected devices that require ac power are connected to properly grounded and working
electrical outlets.
Chapter 4. Service checkout and symptom-to-FRU index 37