HP 540 Maintenance And Service Manual page 80

3. Remove the heat sink (2).
NOTE:
(1), (2), and (3), and the system board components (4), (5), and (6) each time the heat sink is
removed. Thermal pads and thermal paste must be installed on all surfaces before the heat sink
assembly is reinstalled. Replacement thermal material is included with all heat sink, system board,
and processor spare part kits.
NOTE:
UMA memory.
4. Following the 1, 2, 3, 4, sequence stamped into the heat sink, loosen the four Phillips PM2.5×10.0
screws (1) that secure the heat sink to the system board.
72 Chapter 4 Removal and replacement procedures
The thermal material must be thoroughly cleaned from the surfaces of the heat sink
Steps 4 and 5 apply only to computer models equipped with graphics subsystems with