How do I reset the drum counter on the a Brother MFC-7840W???

The wire is on the drum (where the toner cartridge fits in). The green or blue piece slide cleans the coroner wire.

Maybe you left part of the seal or a piece of tape on the toner unit. The actual drum should look green, and it should be perfectly smooth (no dents)

Remove old drum from the unit.
Remove toner and install in the new drum.
Place Drum Back in the machine, leave cover open.
With the cover door open Hold Clear/Back button (about 5 sec.) until the Lcd reads Replace/Reset Drum? yes? no?
Press 1 for yes and close cover.
The machine will cycle and restart, once it says ready the counter has been reset to 100%

If you have the manual follow the steps for trouble shooting.
It will tell you to remove the drum, remove toner, clean corona wire and reinstall. If that does not solve the issue it will recomend replacing the drum. You can check your drum life by going to menu- press machine info, choose option 3 drum life and press ok. This will show you the remaining percentage of your drum if the number shows less than 25% replace the unit.
If it shows more than 50% you can reset the drum counter allowing the machine to read it as a new unit.( Bare in mind this will change the usage meter back to 100%, you will have to keep an eye out for print defects or light pages as this will signal the end of the drum life) to reset page counter remove the drum from the machine, with the front door open press Clear/back until the lcd displays reset drum yes? no? press 1 for yes and reinstall drum. The machine will cycle until ready; if this still has not cleared the message you will need to contact brother for a manual reset or service.

hello, i am going to ball park this, with machine on, open up front cover as if you are going to replace toner, press the clear button, on the display it may say, new drum press 1 for yes 2 for no, then close front cover. normally the drum comes with the instructions on this, but sometimes its missing, but also brothers web site has the info on this. i work on these alot so most of the resets are the same

To reset MFC-7840W drum count use the following steps.

1. open the front cover (leave open).
2. Press clear/back.
3. Then confirm the new drum install by pressing 1.
4. The display will indicate accepted.
5. Then close the front cover.

This should be done each time the drum unit is replaced.

Hi,

This message would continue to appear if the drum unit counter was not reset when you installed a new drum.
To reset the drum unit counter, follow the instructions below:

• Press Menu on the Control Panel.

• Press the Up or Down Arrow key to select Machine Info..

• Press OK.

• Press the Up or Down Arrow key to select Reset Menu.

• Press OK.

• Press the Up or Down Arrow key to select Drum.

• Press OK.

• Press 1 to reset the drum unit counter.

Thank you !!

The drum is the photosensitive roller that the image is charged onto so I'm afraid cleaning the corona wire won't help. If the drum is removeable try reseating it, otherwise it looks like you may need to buy a new drum kit for it.

open the front cover of the machine then press clear back it will say replace drum? press ok
the quality will probably start getting pretty bad as you will be using the drum passed it's life

Has two situations:

1. The corona wire on the drum unit needs to be cleaned.Clean the corona wire on the drum unit.
2. The drum unit has reached the end of its life. Replace the drum unit.