HP Pavilion DV4-2155 Maintenance And Service Manual page 98

Removal and replacement procedures
Remove the heat sink assembly:
1. Turn the system board upside down with the front toward you.
2. Loosen the four captive Phillips PM2.0×10.0 screws 1 that secure the heat sink assembly to the system board.
3. Remove the Phillips PM2.5×3.0 screw 2 that secures the heat sink assembly to the system board.
4. Remove the heat sink assembly 3.
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Due to the adhesive quality of the thermal material located between the heat sink assembly and system board
components, it might be necessary to move the heat sink assembly from side to side to detach the assembly.
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The thermal material must be thoroughly cleaned from the surface of the heat sink assembly and the system board
each time the heat sink assembly is removed. Thermal material is applied to the heat sink to correspond with
components on the system board as follows: the processor 1, the Northbridge chip 2, and the capacitors 3.
Replacement thermal material is included with all system board, fan/heat sink assembly, and processor spare parts.
Reverse this procedure to install the heat sink assembly.
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