Have a Brother HL2270DW laser printer. Great printer, except that the starter cartridge lasted a measly 210 pages.
First, I tried this. Which didn’t work.
Then I ordered these inexpensive replacement cartridges from Amazon. Wish me luck.
Then I found this solution, which works. The post, originally by Phiolle, says:
Please do the following steps to reset the toner sensor.
– Open the front cover and leave open while completing the following steps.
– Turn the printer off.
– Hold the ‘go’ button while turning the printer on. All lights should be on.
– Release the ‘go’ button (or “start’ button).
– Press the ‘go’ button (or “start’ button) 2 times.
– Pause. All panel lights should be on.
– Press the ‘go’ button (or “start’ button) 5 times.
The toner light should be off. (error may be flashing)
The paper light should be on or flashing.
– Close cover. The ready light should be the only light on.
It works. Quoted here for posterity and google-ability.