HP ProBook 450 G2 Notebook PC HP ProBook 455 G2 Notebook PC Maintenance and Service Guide
Heat sink assembly
All heat sink assembly spare part kits include replacement thermal material.
Description Spare part number
Heat sink assembly for use in HP 450 (Intel) models:
For use in models with UMA graphics 768048-001
For use in models with discrete graphics and all processors except for the Intel i7-4558U 768050-001
For use in models with discrete graphics and an Intel i7-4558U processor 768049-001
Heat sink assembly for use in HP 455 (AMD) models:
For use in models with UMA graphics 767435-001
For use in models with discrete graphics 767434-001
Before removing the heat sink assembly, 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 43).
5. Remove the following components:
a. Service doors (see
Service door on page 44).
b. Hard drive (see
Hard drive on page 46)
c. Optical drive (see
Optical drive on page 50)
d. WLAN module (see
WLAN/Bluetooth combo card on page 52)
e. WWAN module (see
WWAN module on page 54)
f. Keyboard (see
Keyboard on page 56)
g. Top cover (see
Top cover on page 64)
h. System board (see
System board on page 84)
Remove the heat sink assembly:
1. Position the system board upside-down.
2. Models are available with either UMA or discrete graphics. The heat sink on discrete models includes 2
additional screws. Refer to the following steps that match your model:
Discrete models:
a. To remove the discrete heat sink assembly, in the order indicated on the heat sink, loosen the 6
captive Phillips screws (1) that secure the heat sink to the system board.
92 Chapter 6 Removal and replacement procedures for Authorized Service Provider parts