Brother HL 4150CDN - Manual (Page 118)

Routine Maintenance
112
5
h
Slide the belt unit back into the machine. Make sure the belt unit is level and fits firmly into place.
i
Make sure the green lock lever (1) is in the release position as shown in the illustration.
j Match the guide ends (2) of the drum unit to the c marks (1) on both sides of the machine, then gently
slide the drum unit into the machine until it stops at the green lock lever.
1
1
2