86     IBM Desktop System HMM
Removals and Replacements 
BEFORE REMOVING ANY FRU, POWER-OFF THE 
COMPUTER, UNPLUG ALL POWER CORDS FROM 
ELECTRICAL OUTLETS, THEN DISCONNECT ANY 
INTERCONNECTING CABLES.
ATTENTION: 
 The system board, processors, adapter 
cards, DIMMs, and upgrade processors can be 
damaged by electrostatic discharge. Use an 
electrostatic discharge (ESD) strap to establish 
personal grounding. If you don't have an ESD 
strap, establish personal grounding by 
touching a ground point with one hand before 
touching the static-sensitive FRUs.
The arrows in the removals and replacements 
procedures show the direction of movement to 
remove a field-replaceable unit (FRU), to turn a 
screw, or the direction to press a tab to release the 
FRU.
Begin all removals by removing the cover (and rear 
cover, if applicable).
When other FRUs must be removed prior to removing 
the failing FRU, they are listed at the top of the page. 
Go to the removal procedure for each FRU listed, 
remove the FRU, and then continue with the removal 
of the failing FRU.
To replace a FRU, reverse the removal procedure 
and follow any notes that pertain to replacement.
Before disconnecting any cables, note their location 
and orientation. Reinstall any new FRUs with cabling 
in their original location.