IBM MT 2631, A21M, A22P, A22M, A21P, A20M General descriptions, Read this first, What to do first

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

vOnly certified trained personnel should service the computer.

vRead the entire FRU removal and replacement page before replacing any FRU.

vUse new nylon-coated screws when you replace FRUs.

vBe extremely careful during such write operations as copying, saving, or formatting. Drives in the computer that you are servicing sequence might have been altered. If you select an incorrect drive, data or programs might be overwritten.

vReplace 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.

vA 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 recurs. 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.

vBe careful not to replace a nondefective FRU.

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
__ 5.	Failure symptoms, error codes appearing on the
	display, and beep symptoms
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