HP ProBook 450 G4 Notebook PC and HP ProBook 455 G4 Notebook PC - Maintenance and Service Guide

3. Lift the heat sink from the system board (7).
NOTE: Thoroughly clean thermal material from the surfaces of the system board components (1)(3)
and the heat sink (2)(4) each time you remove the heat sink. All heat sink and processor spare part kits
include thermal material.
4. UMA models: In the order indicated on the heat sink, loosen the 4 captive Phillips screws (1)–(4) that
secure the heat sink to the system board.
80 Chapter 6 Removal and replacement procedures for Authorized Service Provider parts