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

7. Remove the optical drive bracket (2).
Reverse this procedure to reassemble and install an optical drive.
Power button board
Description Spare part number
Switch cover with power button board
For use in computers with 17.3-in displays 598675-001
For use in computers with 15.6-in displays 598674-001
Before removing the power button board, 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 switch cover and keyboard (see
Switch cover and keyboard on page 51).
58 Chapter 4 Removal and replacement procedures