HP ProBook 4520s Maintenance And Service Manual page 23

Component
(1) USB ports (2)
(2) RJ-11 (modem) jack (select models only)
(3) Optical drive (select models only)
(4) Optical drive light (select models only)
(5) AC adapter light
(6) Power connector
Description
Connect optional USB devices.
Connects a modem cable.
Reads optical discs and, on select models, also writes to optical
discs.
Blinking: The optical drive is being accessed.
●
On: The computer is connected to external power and the
battery is charging.
●
Off: The computer is not connected to external power.
Connects an AC adapter.
Right-side components
15