IBM MT 9441 Laptop User Manual


 
FRU replacement notices
This section contains notices related to removing and replacing parts. Read this
section carefully before replacing any FRU.
Screw notices
Loose screws can cause a reliability problem. In the ThinkPad computer, this
problem is addressed with special nylon-coated screws that have the following
characteristics:
v They maintain tight connections.
v They do not easily come loose, even with shock or vibration.
v They are harder to tighten.
v Each one should be used only once.
Do
the following when you service this machine:
v Keep the screw kit (for the P/N, see “Miscellaneous parts” on page 159) in your
tool bag.
v Always use new screws.
v Use a torque screwdriver if you have one.
Tighten
screws as follows:
v Plastic to plastic
Turn an additional 90 degrees after the screw head touches the surface of the
plastic part:
90 degrees more
(Cross-section)
v Logic card to plastic
Turn an additional 180 degrees after the screw head touches the surface of the
logic card:
180 degrees more
(Cross-section)
v Torque driver
If you have a torque driver, refer to the “Torque” column for each step.
v Make 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.
v Ensure torque screwdrivers are calibrated correctly following country
specifications.
Retaining serial numbers
This section includes the following descriptions:
v “Restoring the serial number of the system unit” on page 53
FRU replacement notices
52 MT 8747, 8749, 9440, 9441, 9442, 9443, and 9448