My toner light stays on even after I change my toner. Fortunately, there is a way to reset it.
Switch your printer off.
Open front cover and keep it open.
Press „Go“ button and hold it while turning printer on. Hold “Go” until „toner“, „drum“ and „error“ light stays on.
Then press „Go“ button twice and wait again until „toner“, „drum“ and „error“ lights stay on.
Then press „Go“ button five times and wait for „error“ light to start blinking. It just warns you front cover is still open.
Close front cover. It should be fixed now.