[Syonyk]

No. They just run X pages and assume the cartridge is empty.

You can reset it with some faintly annoying incantations, and I'd suggest doing so until you notice actual print quality issues. Especially on black.

The logic is... reasonably sound from a print quality perspective. "We know the cartridge can print XXXX pages of reasonable coverage without any fading/dropouts/etc. If the user replaces it at that point, they will never have any print issues." If your goal is "flawless printing," it's a reasonable enough path. It's just not particularly cost effective for the end user. It is, however, cheaper and more profitable than actual toner level sensor/mixing device/etc.

But, yes, there's a hidden menu to reset the toner counter on Brother, and in my experience, there's at least another 50% of rated capacity pages lurking in the cartridges unless you print very toner-heavy pages.

[actionfromafar]

You can gently turn the cartridge over and, back and forth. This will shake toner loose, and you can turn a "gray" cartridge black again.

But you may also get a little toner on you or the floor, so beware.

[Syonyk]

Yes, and if you're trying to save every penny, that's reasonable. Brother doesn't prevent you from doing this, you just have to look up the toner counter reset process, which is trivially found online.

It's exceedingly unreasonable for something like a small office printer to have people constantly reprinting things because the toner is almost, but not entirely out, so please remove the cartridge, shake it gently, etc. Remember, the paper you're spending on partial prints and the toner you're applying isn't free either, and people's time isn't, either. Neither is the carpet cleaning of the toner spot in front of the printer from people trying to stretch it.

I'll reset the counter on mine, give it a shake, and run it until I see any impact on printing, but as soon as I notice any streaking, I just replace the cartridge. It's not worth the hassle to fight for 100 pages of toner to me at this point in my life.

[analog31]

The incantations are printed out and taped to the side of my Brother printer. I can live with light prints for a while. Until I got a recent tablet device, a lot of my prints were sheet music that was used once.