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
Errors”
on
page
69).
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
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
the
system
board”
on
page
63).
108
Hardware
Maintenance
Manual