Toner for fax machine 2920

Your machine is a laser type fac (not inkjet). It does,t use ink, but toner. To learn how to replace the toner cartridge you should read the User's Guide.
You can download it from here: Brother FAX-2920 User's Guide
manual.
Look for section "Troubleshooting and routine
maintenance" / Replace the Toner Cartridge / How to replace the toner cartridge and Replacing the Drum Unit (pags. 112 and following of the User's Guide).

please reset toner using reset software or printed paper count reset

Please do not be offended by any of the suggestions. I do not assume anything.
Toner can become "caked" slightly hardened, so if you have the opportunity to shake the toner inside its container, do so.
If you have replaced an entire unit, confirm protective strip has been removed from toner before installing into cartride or its proper placement.
These two suggestions are preliminary to comprehensive troubleshooting.
Try that

Did you pull the plastic tape on the cartridge?

You need to go buy a Brother DR-350 drum unit cartridge. The drum unit is the thing that the toner cartridge (TN-350) clicks into. Pull out the drum/toner unit and separate the two halves. Place your TN-350 into the new DR-350 cartridge and put back in the printer.

Where did you get the toner cartridge? The TN-350 has one the side with the gearing what is called a flag gear. The "flag" presses a button in the machine to tell the machine a new cartridge has been installed. If your cartridge was an inexpensive one off the internet it may have not been reset and I would return it. It is easy to reset, but if it isn't done I would like to know what else they didn't do. If it is an OEM or you are assured of the quality there is a trick you can try.

Locate where the flag gear is, on the back of the cartridge on the geared side, and place a piece of electrical tape over where it should be. Reinstall the cartridge and wait for the error it will definately throw. After that remove the tape and reinstall the cartridge again. Hopefully that works.

You didn't include the model, but here are instructions for the Fax-2820; it should work for any of the models that use the TN-350 toner:

1. With the power on, open the front cover.
2. Press the Options key. The display will read "Change Drum?"
3. Press Start.
4. Press 1 0.
5. The display reads "Accepted" for about 2 seconds, then change to "Cover Open."
6. Close cover. The "Replace toner" message should be cleared.

Normally, inserting a new cartridge (with the power on) will reset the toner counter, and you won't have to do any of this.

First, the obvious

• Did you gently rock the toner cartridge from side to side to evenly distribute the toner?
• Did the cartridge "click" into place?(did lock lever pop up when it was inserted)
  
• Did you replace the protective cover securely?

Another thing to check is cleaning the Corona wire inside by sliding the Blue tab back and forth several times. Important to return the Blue tab back to the "Home" position afterward.
If you've done ALL of these steps correctly, and the low toner message is still there, a service call is in order. Best of luck with your machine!

TN-350

THE DRUM AND THE TONER CARTRIDGE IS IN SIDE OF THE MACHINE.OPEN THE COVER AND YOU WILL SEE THE DRUM CARTRIDGE,TTAKE OUT THE DRUM UNIT. ITTELLS YOU ON THE DRUM UNIT THE NUMBER DR    IT IS SOLD IN OFFICE DEPOT OR OFFICE MAX OR STAPLES, MAKE SURE THAT YOU ONLY USE BROTHER PRODUCTS. GOOD LUCK BROTHER SR TECH