BROTHER MFC 7820N MACHINE PUT IN NEW DRUM, CHANGE DRUM MESSAGE COMES ON. PUT IN NEW TONER, TONER END OF LIFE MESSAGE COMES ON.

I fail to see why you are covering up the toner sensor led's when you have a new cartridge fitted?
Also if you are using a recycled toner from a very well known uk shop that refills toners and ink then you may well have broken the drive gear that stirs the toner. i have seen this six times and their toners do this.
It could well be one of the pitfuls of recycled toners.

ok here is the procedure for that.

1) open the front cover of the printer ..that is the cover that allows you to pull out the drum/toner, but leave them inside the machine

2)push the options button:located on the left side of the control pad)

3) type *00 on the keypad

this will reset the printer and the "toner end of life" message should go away, leaving your printer thinking it is brand new again !

If you want to reset your Brother MFC 9440N machine so you no longer have the error message: Toner End of Life, do the following:

1. Open the front cover of the 7820N, that is, the cover that allows you to pull out the toner and drum, but don't pull out the drum/toner.
2. Push the button: Options (located on the left of the control pad).
3. Type: *00 on the keypad.

The Brother MFC 9440N should be reset and the Toner End of Life message should disappear. Warning, this may void your warranty and ultimately damage your machine if you are reusing or refilling your cartridges, but you should already know that. Hope this helps.

Brother International - Support for your Brother Product

go to this link and i am not sure but i think the one at the top of the page might help you out.. toner cartridge for the MFC 7820n printer It still says the toner life is...

I found the following post on another site. It appears to work. If you want to reset your Brother MFC 7820N machine so you no longer have the error message: Toner End of Life, do the following:

1. Open the front cover of the 7820N, that is, the cover that allows you to pull out the toner and drum, but don't pull out the drum/toner.
2. Push the button: Options (located on the left of the control pad).
3. Type: *00 on the keypad.

The Brother MFC 7820N should be reset and the Toner End of Life message should disappear. WARNING: This may void your warranty and ultimately damage your machine if you are reusing or refilling your cartridges, but you should already know that. Hope this helps.

Depends on the usage of the machine. If hardly used, you should get a years worth. But here's what you can do:

Open front cover

Remove drum unit and toner cartridge assembly

Put drum unit and toner cartridge assembly back in machine, but do no close front cover.

Press Clear/Back
You will get a message "Replace Drum?"
Select Yes to confirm

Description:
This message would continue to appear if the drum counter was not reset when you replaced the drum. To reset the drum counter, follow the instructions listed below.


Open the front cover.
Press the Options key on the control panel.
The display will show "REPLACE DRUM - 1.YES 2.NO".
Press 1 to reset the drum count.
Close the front cover.

Try removing the new toner cartridge from the machine, and shake it up and down and sideways, over a newspaper. Then, put it back in the machine and see if that helps. Sometimes, especially if the new cartridge was exposed to high temperatures or humidity before you got it, the toner SETTLES inside. Shaking it up can usually help.

did you reset the toner life?

open the front cover, press the option button, on the screen will display ''reset toner life 1 yes 2 no ''
press 1 and close the cover.

toner life reseted