HP ProDesk 400 G4 SFF Hardware Reference Manual page 39

14. Slide the optical drive through the front bezel all the way into the bay (1) so that it locks in place (2).
15. Connect the power cable (1) and data cable (2) to the rear of the drive.
16. Replace the access panel.
17. Reconnect the power cord and any external devices, then turn on the computer.
18. Lock any security devices that were disengaged when the access panel was removed.
Removing and installing drives 31