Sony CDU625 User Manual page 25

When the drive's right side is down
To facilitate disc handling, set the disc locks B, C and D into the
locked position, and leave the disc lock A in the unlocked position.
D
A
Top side
Right side
B C
When the drive's left side is down
To facilitate disc handling, set the disc locks A, C and D into the
locked position, and leave the disc lock B in the unlocked position.
C
B
Top side
Left side
D A
25
Operating the Drive