[jessriedel]

Hmm, I have been using generic toner in Brother DCPL2540DW and HL-L2370DWXL laser printers for years without issue.

My vague impression is that Brother printers try to detect whether a cartridge is for the correct printer model, but not whether the cartridge is Brother brand. So long as the generic cartridge has a chip that says "I am designed for this printer", it should work.

(The worst they do is advise you on the website to buy "genuine Brother ink" because of the increased risk of jams, cloggings, etc with generics. Im sure this is overplayed, but its not an altogether imaginary risk.)

Is it possible that your generic cartridge is just crummy? There really are a ton of Chinese generic cartridge brands, and it would not be surprising if some are crap. Maybe try a different brand of generic?

[praptak]

I cannot rule this out. This happened twice so far, with a different cartridge brand each time.

Also, the last time two slots failed at once, or in a very short timespan (black and yellow). Unfortunately I don't remember which slot failed when it happened for the first time.

So, the data suggests it's the printer but as always, more data is needed.