Brother HL HL-4050CDN User Manual page 148

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
Routine Maintenance
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