Brother HL-4050CDN EN - Manual (Page 148)

Routine Maintenance
139
6
j
Insert the original orange packing material for locking the belt unit as shown in the illustration
k
Put a piece of paper (letter or A4) on the belt unit to prevent damage to the belt unit.
l
Make sure that the gray lock lever (1) is in the up position and put the drum unit in the printer. Push down
the gray lock lever (1).
1 1