Brother HL-4150CDN User Manual page 121

Routine Maintenance
f
Make sure the green lock lever (1) is in the release position as shown in the illustration.
g
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
2
h
Turn the green lock lever (1) clockwise to the lock position.
1
1
5
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