Compaq 325 and 326 Notebook PCs HP 425 and 625 Notebook PCs - Maintenance and Service Guide

Heat sink
NOTE: The heat sink spare part kit includes replacement thermal material.
Description Spare part number
Heat sink for use in computers with UMA graphics subsystems 611804-001
Heat sink for use in computers with discrete graphics subsystems NB 611805-001
Heat sink for use in computers with discrete graphics subsystems CPU 615355-001
Before removing the heat sink, follow these steps:
1. Shut down the computer. If you are unsure whether the computer is off or in Hibernation, turn
the computer on, and then shut it down through the operating system.
2. Disconnect all external devices connected to the computer.
3. Disconnect the power from the computer by first unplugging the power cord from the AC outlet
and then unplugging the AC adapter from the computer.
4. Remove the battery (see
Battery on page 48).
5. Remove the service door (see
Service door on page 49).
6. Remove the fan (see
Fan on page 59).
Remove the heat sink on computers with UMA graphics subsystems:
1. Position the computer right-side up with the front facing you.
2. Following the numbered sequence stamped into the heat sink, loosen the captive screws (1) and
(2) around the processor.
3. Raise the end of the heat sink (3) to free it from the system board components and then remove
the heat sink (4) from the system board.
60 Chapter 4 Removal and replacement procedures