Brother HL-4040CN Service Manual page 146

(3) Remove the Toner filter frame ASSY from the Paper eject ASSY DX/SX.
Paper eject ASSY DX/SX
Assembling Note:
When assembling the fuser unit, make sure that the two Harnesses are placed in the
groove and under the rib of the Plastic frame. If they are not, then correct them as shown
in the figure below.
3a
3b
Fig. 3-30
Harness
Plastic frame
Fig. 3-31
3-38
Toner filter frame ASSY
Harness
Confidential