IBM 149H Laptop User Manual


 
ThinkPad i Series 1400 Hardware
Maintenance Manual
Read This First
Before you go to the check procedures, be sure to read
this section.
Important Notes
Only certified trained personnel should service the
computer.
Read the FRU service procedures before replacing
any FRUs.
Be extremely careful during write operations such as
copying, saving, or formatting. Drives in the computer
that you are servicing might have been rearranged or
the drive startup sequence might have been altered. If
you select an incorrect drive, data or programs could
be overwritten.
Ensure that you replace FRUs with the appropriate
model. When you replace the FRU, make sure that
the model of the machine and FRU part number are
correct by referring to the part list.
FRUs should not be replaced because of a single,
unreproducible failure. Single failure can occur for a
variety of reasons that have nothing to do with a
hardware defect, such as: cosmic radiation,
electrostatic discharge, or software error. FRU
replacement should be considered only when a recur-
ring problem exists. In this case, clear the error log
and run the test again. Do not replace FRUs if log
errors do not reappear.
Be careful not to replace a non-defective FRU.
How to Use Error Messages
Use the error codes displayed on the screen to diagnose
failures. If more than one error code is displayed, begin the
diagnosis with the first error code. The cause of the first
error code can result in the other false error codes being
displayed.
How to Diagnose Multiple FRUs
If the adapter or device has more than one FRU, the error
code could be caused by either FRU. Before replacing
multiple FRUs, try removing or exchanging each FRU one
by one in the designated sequence, to see if the symptoms
change.
ThinkPad i Series 1400
1