FRU replacement notices
This chapter presents notices related to removing and replacing parts. Read this
chapter carefully before replacing any FRU.

Screw notices

Loose screws can cause a reliability problem. In the ThinkPad Notebook, this
problem is addressed with special nylon-coated screws that have the following
characteristics:
vThey maintain tight connections.
vThey do not easily come loose, even with shock or vibration.
vThey are harder to tighten.
vEach one should be used only once.
Do the following when you service this machine:
vKeep the screw kit (for the P/N, see “Miscellaneous parts” on page 350) in your
tool bag.
vAlways use new screws.
vUse a torque screwdriver if you have one.
Tighten screws as follows:
vPlastic to plastic
Turnan additional 90 degrees after the screw head touches the surface of the
plastic part:
90degrees more
(Cross-section)
vLogic card to plastic
Turnan additional 180 degrees after the screw head touches the surface of the
logic card:
180degrees more
(Cross-section)
vTorquedriver
If you have a torque driver,refer to the “Torque” column for each step.
vMake sure that you use the correct screw.If you have a torque screwdriver,
tighten all screws firmly to the torque shown in the table. Never use a screw
that you removed. Use a new one. Make sure that all of the screws are
tightened firmly.
vEnsure torque screw drivers are calibrated correctlyfollowing country
specifications.
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