HP ProBook 4520s Notebook PC and HP ProBook 4720s Notebook PC - Maintenance and Service Guide

Description Spare part number
Heat sink for use in computers with UMA graphics subsystems 598676-001
Heat sink for use in computers with discrete graphics subsystems 598677-001
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 50).
5. Remove the following components:
a. Switch cover and keyboard (see
Switch cover and keyboard on page 51).
b. Thermal shield (see
Thermal shield on page 62).
Remove the heat sink:
●
For computers with discrete subsystem memory on the system board, follow these steps:
1. Position the computer right-side up with the front toward you.
2. Following the sequence stamped into the heat sink, loosen the six captive screws (1), (2), (3),
(4), (5), (6), around the processor.
70 Chapter 4 Removal and replacement procedures