Brother HL-4200CN Service Manual page 53

9) With the flat part of the cartridge facing the rear, align the orange rollers on both
sides of the print head cartridge with the slots in front of the arrows on the printer,
and gently lower the cartridge into the printer.
Note:
Lowering the cartridge into the printer without correctly aligning the rollers with the
slots can damage the cartridge.
Do not allow the surface covered with a protective sheet to come into contact with
anything.
10) Pull the protective sheet on the cartridge straight up to remove it, as illustrated.
Note:
Do not touch the transfer roller (black part). Make sure that nothing touches or
scratches the roller surface. Scratches or oil from your hands on the roller
deteriorates print quality.
11) Close the paper outlet cover.
Protective sheet
Fig.2-24
Do not touch the transfer roller
Fig.2-25
Fig.2-26
II-10
Orange rollers