Replacing A Power Supply Unit - Sun Microsystems SPARC Enterprise T5120 Installation And Service Manual

4.2

Replacing a Power Supply Unit

This is a hot replacement procedure, meaning that the PSU can be replaced while the
system is still running, provided that a second PSU is working properly.
1. Use an antistatic strap for this procedure.
2. Unpack the new power supply unit and set it flat on an antistatic surface.
Caution – Do not rest a PSU vertically. The plastic electrical connector on the back is
breakable.
3. At the front of the defective PSU, turn off the PSU AC switch and verify that the
DC Power LED (
4. Loosen the handle locking screw on the PSU handle.
5. Unlock the PSU by swinging the handle out 90 degrees into the fully open
position. (
6. Place a hand under the PSU to prevent it from falling, then pull the PSU out of
the External I/O Expansion Unit.
Caution – The PSU is heavy (7.5 lb/3.4 kg).
When you can see the warning label on the top of the PSU, the PSU is almost fully
out of the PSU slot.
Caution – Do not allow the rear of the PSU to drop. The connector at the rear of the
PSU can be damaged if it strikes the edge of the slot.
A pivoting flap behind the PSU drops down to prevent loss of cooling air.
) turns off.
)
FIGURE 4-1
Chapter 4 Servicing and Replacing Components 4-3