Chapter 2. General Descriptions; Read This First - IBM ThinkPad X20 Hardware Maintenance Manual

Chapter 2. General descriptions

This chapter includes descriptions for any ThinkPad model
that has the PC-Doctor DOS diagnostics program. Some
descriptions might not apply to your particular computer.

Read this first

Before you go to the checkout guide, be sure to read this
section.
Important notes:
v Only certified trained personnel should service the
computer.
v Read the entire FRU removal and replacement page
before replacing any FRU.
v Use new nylon-coated screws when you replace
FRUs.
v Be extremely careful during such write operations
as copying, saving, or formatting. Drives in the
computer that you are servicing may have had their start
sequence altered. If you select an incorrect drive, data
or programs might be overwritten.
v Replace FRUs only for the correct model. When you
replace a FRU, make sure the model of the machine
and the FRU part number are correct by referring to the
FRU parts list.
v A FRU should not be replaced because of a single,
unreproducible failure. Single failures can occur for a
variety of reasons that have nothing to do with a
hardware defect, such as cosmic radiation, electrostatic
discharge, or software errors. Consider replacing a FRU
only when a problem reoccurs. If you suspect that a
FRU is defective, clear the error log and run the test
again. If the error does not recur, do not replace the
FRU.
v Be careful not to replace a nondefective FRU.
v Service applied by an unauthorized/trained Thinkpad
technician may potentially void your warranty
What to do first: When you do return a FRU, you must
include the following information in the parts exchange
form or parts return form that you attach to it:
1. Name and phone number of servicer
2. Date of service
3. Date on which the machine failed
4. Date of purchase
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