Lexmark MS631
Extremely low print coverage for extended periods of time may cause imaging unit parts to fail before the toner is exhausted.
Regular imaging unit
66S0ZA0
Return Program imaging unit
66S0Z00
Understanding imaging unit yield on Lexmark's MS/MX 310, 410, 510, 61x, 71x, and 81x devices.
Avoid printing delays. Install a new imaging unit when the printer prompts you to replace it.