MFC 9450 - CDN shows toner end of life message. The cartridges had been refilled from bottles. This was solved by resetting the flag gear so the printer thought it had a new cartridge. See this link. As stated earlier - works great. http://www.castleink.com/265/cartridge/TN580.pdf

The toner reset is performed on the toner cartridge not the printer menu. If the toner has registered empty don't try to use it unless it has actually been refilled. These cartridges actually do run almost completely empty unlike earlier models. If the cartridge has been filled you can reset the flag gear on the right hand end but correct positioning is crucial.

I just got through this problem, The customer had a "refilled cartridge.
The Flag on the left side near the gearset of the Toner cartridge was not
brought back to the proper position, just undo the three srews and reset the flag.
works like a champ,. your welcome.

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.

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.

I replaced already new toner cartridge for my brother fax machine mfc-2820 but still the on screen message is appearing on the display "TONER LIFE END".
Pls help me to solve this problem.

i solved the brother mfc8860 toner life end problem
hi guys my name is reedwaan. Im new at this site so please listen up 
my brother toner i refilled with toner and inserted it. It said toner life end then i patched the windows close on the sides and still the same problem, then i removed the toner and loosened the two screws on the left by the gears then removed the cover of the gears. 
Right at the back there is a funny looking gear with a spring behind it. All you have to do is pull the spring a little bit clockwise and push the gear back on hooking the spring into it so that the gear is spring loaded. close it up then test it, It took me a while to figure it out but i got it right. 
NB*  The gear that you push on, is the toner reset gear and when you push it on make sure the teeth dont interlock with the second gear on the left of it. If you have any queries mail me on [email protected] 
glad to help out

open front cover, press OPTION button, on the LCD will appear a message "NEW DRUM?" ....DO NOT RESPOND....just type on the keyboard "*00" and there will appear a message "Accepted" and use it in your pleasure.

PS. in any case i blocked with paper labels the viewing windows from transparent plastic on the toner itself....

Mr. Brother, do not try to be smarter than your customer

I just solved my own problem. Try it for yours. I had been using several compatible toners for the MFC-8460N with no problems until today, as I posted earlier. On a hunch, I went to the local office supply store and purchased one original Brothers TN550 toner and put it into the printer and closed the cover. Everything clicked. Toner End Life message gone. I then took that Brother toner out and put the compatible one back in and still everything was fine. Am keeping the original Brother toner as a "kickstarter" if it happens again.

Is the toner cartridge an original Brother or is it remanufactured? The toner cartridge for this model is the TN-350, which has a "flag gear" on the left (gear) side. It is a little plastic piece that sticks out on the new cartridges and, after putting the cartridge in for the first time, it rotates out of the way. This is how the printer knows that the cartridge is new. Some remanufacturers either don't put the flag gear in or they forget to turn it back to the original position when they build the cartridge. So that would be the first thing I would look at.

OK.. I agree that your problem is with the flag gear. However, there is a specific location in which it needs to be situated. The purpose of the flag gear is to trip a reset actuator on the left side of the printer. The correct position of the flag gear needs to be set so the reset actuator is depressed 3/4 of the way AND where the flag gear moves out of the way once this is done. If the flag gear is moved all the way forward, you run a risk of the gear mechanism inside not rotating it out of the way...which could leave you with a 'no cartridge installed' message. When the manufacturer of the toner cartridge made this unit, they decided to put a mark on the side to, evidently, let the assembly team know where to set the flag gear. Great for us :) On the outside plastic piece that you have to remove to get to the flag gear, you will see a diagonal line and a view window. When you rotate the flag gear, you will eventually see a portion of the white gear in that view window. Line up the white gear portion with the bottom of the diagonal line (typically two gear teeth), and you're done. Assemble and run!