HP ProDesk 400 G4 SFF Hardware Reference Manual page 33

8. Slide the optical drive through the front bezel all the way into the bay (1) so that it locks in place (2).
9. Connect the power cable (1) and data cable (2) to the rear of the drive.
10. Connect the opposite end of the data cable to the light blue SATA connector on the system board labeled
SATA1.
NOTE: Refer to System board connectors on page 10
connectors.
11. Replace the front bezel if it was removed.
12. Replace the computer access panel.
13. Reconnect the power cord and any external devices, then turn on the computer.
14. Lock any security devices that were disengaged when the access panel was removed.
for an illustration of the system board drive
Removing and installing drives 25