I can confirm that Brother printers stop working even though the toner still prints perfect pages. I couldn't believe that a company would program a functional product to suicide, so I did some searching on the subject. There used to be a hack that was possible to get Brother printers to continue printing by covering an "eye" on the printer (http://www.fixyourownprinter.com/forums/laser/39806). However, the new Brothers (like my HL2270DW) no longer have this exploit available.
I feel that a company that would deliberately program its toner to stop functioning, is questionable on moral grounds. It is purposeful destruction of value. It hurts the environment and is wasteful.
I was able to get this to work on an HL2140 last year. I just taped a small piece of construction paper over the eye on the cartridge and it happily went about printing for quite some time- I made it through an entire ream before the quality degraded. Since then, I always cover the eye on new cartridges before I insert them and use the quality of the prints, not the printer itself, to let me know when to buy more toner.
Ah yes, you're right. The hole was supposed to be on the toner, but the hole no longer existed on the toner required by my printer (judging by toner/hack pictures I found online and threads discussing the hack for my make). Glad it worked out for you. Don't replace your printer!
I feel that a company that would deliberately program its toner to stop functioning, is questionable on moral grounds. It is purposeful destruction of value. It hurts the environment and is wasteful.