I have a Brother mono laser printer - MFC-L2710DW. It prints 2 sided, something previous printers would not do.
When a toner cartridge started not printing evenly, I took it out and shook it, which 'cured' it for a few copies. Then I put a new cartridge in. It had not given me the "low toner' message that the original cartridge had - on the lcd screen.
Being a curious sort of bloke, I got a screwdriver and pulled the old cart apart, still a considerable amount of toner dust inside. [don't do this in the lounge room!].
I just wondered if anyone has a trick to make it use more of the toner.?
On a previous Hewlett Packard laser printer, you could cover a spot on the toner cartridge with black tape, and it would print well long after it would normally have given the 'low toner' message.