HP 550 Maintenance And Service Manual page 81

3. Remove the heat sink (2).
NOTE: The thermal material must be thoroughly cleaned from the surfaces of the heat sink (1) and
(2), the processor (3), and graphics system component (4) 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.
Thermal material is included with all heat sink and processor spare part kits.
Reverse this procedure to install the heat sink.
Component replacement procedures 73