I am changing the ink cartridge i put the new one in and it keeps saying End of life and it has a new cartridge what do i do

Here is the solution that will reset the count and allow your fully functional toner cartridge (the one the printer tells you is empty) to continue to work.

Open the front cover.
Press options button.
Press the start button.
Press + or up arrow button 10 times.
Press set button.

You have to do this with a long pause or the system will reset and you will have to start over.

Good luck.

You just need to override the software, there is a simple fix for it, just check the tutorial: Affordable Brother TN350 Toner Cartridge

This is from Brother's support page at http://www.brother-usa.com/FAQs/Solution.aspx?FAQID=200000006154&Sympt=Why+does+the+message+Toner+Life+End+continue+to+appear+on+the+LCD+after+I+replaced+the+toner+cartridge%3f&Model=23&ProductGroup=5&Keyword=toner&ProductID=DCP7020:

Description of Problem 100000005096
Why does the message "Toner Life End" continue to appear on the LCD after I replaced the toner cartridge?

Description of Solution 200000006154
Brother strongly recommends that customers use only genuine Brother drum units and/or toner cartridges. Each Brother laser printer is designed to work at pre-set temperatures that are matched exactly to each of our individual toner formulations. Each individual component is designed to work with the other to ensure quality and reliability. Using non-Brother supplies may affect the hardware performance, print quality and machine reliability. The Brother limited warranty does not apply to any problem that is caused by the use of third party drum units, toner cartridges or toner.

1. Did you replace the toner cartridge with a NEW, out of the box, genuine Brother TN350 toner cartridge? If no, you will need to purchase and install a new Brother TN350 toner cartridge.

If a toner cartridge from another machine was installed (even if there's still toner left in the used cartridge) or a TN Starter toner cartridge (included with the purchase of a machine) was installed, the message "Toner Life End" would continue to appear on the display. You will need to purchase and install a new Brother TN350 toner cartridge.

2. If you installed a new TN350 toner in an attempt to resolve the Toner Life End message, verify the toner cartridge is installed correctly by following the steps listed below:

a. Open the front cover.

b. Lift the drum unit slightly and pull it out. Place the drum unit on a drop cloth or large piece of disposable paper to avoid spilling and scattering the toner.

c. Remove the toner cartridge from the drum by holding down the lock lever (blue tab) on the left side of the drum unit and lift the toner out.

NOTE: Handle the toner cartridge carefully. If toner scatters on your hands or clothes, immediately wash it off with cold water.

d. Gently rock the toner cartridge from side to side five or six times to distribute the toner evenly inside the cartridge.

e. Place the toner cartridge into the drum (be sure it clicks into place).

f. Clean the primary corona wire inside the drum unit by gently sliding the blue tab on the top of the cartridge from right to left several times. Return the blue tab to the home position before reinstalling the drum unit assembly.

g. Reseat the drum unit into the machine.

h. Close the front cover.

If the problem continues and you installed a NEW, out of the box, genuine Brother TN350 toner cartridge, and your machine is within warranty, you can locate a Brother Authorized Service Center (ASC) in your area by clicking on the link below:
http://www.brother-usa.com/service/default.aspx or contact Brother Customer Service by calling 1-877-Brother (1-877-276-8437) Monday through Friday, excluding holidays.

If your machine is out of warranty, you can locate a Brother Authorized Service Center using the information listed above