2.1.2 Upgrade and Repair Units (URU)
Upgrade and Repair Units are non hot-plug components that can be ordered 
separately to be installed as options (Upgrade Units) or are available to the 
customer through customer self service (Repair Units).
I Server management error messages and diagnostic indicators on the 
front panel and system board will report defective Upgrade and Repair 
Units as customer replaceable CSS components.
Upgrade and repair procedures involve shutting down and opening the server.
V CAUTION!
The device may be seriously damaged or cause damage if it is opened 
without authorization or if repairs are attempted by unauthorized and 
untrained personnel.
Components that are handled as Upgrade Units
– Processors (upgrade kits)
– Optical disk drives
– Expansion cards
– Battery backup units
– Memory modules
– Front VGA module
Components that are handled solely as Repair Units
– CMOS battery
Upgrade and Repair Units (URU)