IBM MT 2877, Hardware Maintenance Manual

Page: 77 / 220

Removing and replacing a FRU
This section presents directions and drawings for use in
removing and replacing a FRU. Be sure to observe the
following general rules:
1. Do not try to service any computer unless you have
been trained and certified. An untrained person runs
the risk of damaging parts.
2. Before replacing any FRU, review “FRU replacement
notices” on page 67.
3. Begin by removing any FRUs that have to be removed
before the failing FRU. Any such FRUs are listed at the
top of the page. Remove them in the order in which
they are listed.
4. Follow the correct sequence in the steps for removing
the FRU, as given in the drawings by the numbers in
square callouts.
5. When turning a screw to replace a FRU, turn it in the
direction as given by the arrow in the drawing.
6. When removing the FRU, move it in the direction as
given by the arrow in the drawing.
7. To put the new FRU in place, reverse the removal
procedure and follow any notes that pertain to
replacement. For information about connecting and
arranging internal cables, see “Locations” on page 180.
8. When replacing a FRU, use the correct screw as
shown in the procedures.
DANGER
Attention: After replacing a FRU, do not turn on the
computer until you have made sure that all screws,
springs, and other small parts are in place and none are
loose inside the computer. Verify this by shaking the
computer gently and listening for rattling sounds. Metallic
parts or metal flakes can cause electrical short circuits.
Attention: The system board is sensitive to, and can be
damaged by, electrostatic discharge. Before touching it,
establish personal grounding by touching a ground point
with one hand or by using an electrostatic discharge (ESD)
strap (P/N 6405959).
Before removing any FRU, turn off the computer,
unplug all power cords from electrical outlets,
remove the battery pack, and then disconnect any
interconnecting cables.
Removing and replacing a FRU
ThinkPad T43 Series
71