Power Supply - HP dc7900 - Convertible Minitower PC Service & Reference Manual

4. Apply the thermal grease provided in the spares kit to the top of the processor and install the
heatsink atop the processor.
5. Go to step 7.
6. If using a new heatsink, remove the protective covering from the bottom of the heatsink and place
it in position atop the processor.
7. Secure the heatsink to the system board and system board tray with the four captive screws and
attach the heatsink control cable to the system board.
CAUTION:
X) to evenly seat the heatsink on the processor. This is especially important as the pins on the
socket are very fragile and any damage to them may require replacing the system board.
NOTE: After installing a new processor onto the system board, always update the system ROM to
ensure that the latest version of the BIOS is being used on the computer. The latest system BIOS can
be found on the Web at: http://h18000.www1.hp.com/support/files.

Power Supply

WARNING!
active AC outlet. To avoid possible personal injury and damage to the equipment the power cord should
be disconnected from the computer and/or the AC outlet before opening the computer.
1. Prepare the computer for disassembly
2. Remove the access panel
3. Rotate the drive cage up and disconnect the power cables from all of the drives.
4. Disconnect the power cables from the system board.
5. Rotate the power supply to its full upright position.
6. Release the power supply cables from the cable retaining clips on the bottom of the chassis and
under the drive cage.
Figure 8-64
Heatsink retaining screws should be tightened in diagonally opposite pairs (as in an
Voltage is always present on the system board when the computer is plugged into an
(Computer Access Panel on page
Cable routing
(Preparation for Disassembly on page
125).
118).
Power Supply 169