Brother MFC-9840CDW - Page 41

Confidential
1-22
Error code 7D
Drum Error
Slide the Green tab on Drum Unit in each color. Refer to the User’s
Guide for the procedures.
Dirt on drum unit
User Check
- Clean the corona wire in the drum unit.
- Replace the drum unit with a new one.
Step Cause
Remedy
1 Dirt or dust on drum unit
electrodes
Clean the electrodes of the main body and the
drum unit. (Refer to Fig. 1-1 (P1-37).)
2 Charge HVPS PCB failure Replace the charge HVPS PCB ASSY.
3 Engine PCB failure Replace the engine PCB ASSY.
Error code 82
Calibrate
Calibration failed. Press start, and try again.
Density patch measurement is not completed normally when implementing calibration from the
control panel.
User Check
- Check if there is a scratch, dirt or the like on the belt unit. If there is, replace the belt unit
with a new one.
- Check if the genuine toner cartridges are installed in the correct order of colors.
Step Cause
Remedy
1 Density sensor shutter not
operating smoothly or
catching in some position
Correct smooth operation of the density sensor
shutter.
2 Harness connection failure of
density sensor holder ASSY
Check the harness connection of the density
sensor holder ASSY and reconnect it.
3 Density sensor failure Replace the density sensor holder ASSY.
4 Transfer HVPS PCB failure Replace the transfer HVPS PCB ASSY.
5 Engine PCB failure Replace the engine PCB ASSY.