HP ProBook 4320s, 4321s, 4420s, and 4421s Notebook PC

Speakers
Description Spare part number
Speakers for use in computer models with 33.8-cm (13.3-in) displays 599566-001
Speakers for use in computer models with 33.8-cm (13.3-in) displays; includes metallic heat shield 663539-001
Speakers for use in computer models with 35.6-cm (14.0-in) displays 605559-001
Speakers for use in computer models with 35.6-cm (14.0-in) displays; includes metallic heat shield 663540-001
Before removing the speakers, 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 57).
5. Remove the switch cover and keyboard (see
Switch cover on page 59).
Remove the speakers:
1. Position the computer right-side up with the front toward you.
2. Disconnect the speaker cable (1) from the system board.
NOTE: The two speakers are connected with a single cable.
3. Remove the two Phillips PM2.5×3.0 screws (2) that secure the speakers to the base enclosure.
68 Chapter 4 Removal and replacement procedures