Pretty much what RMCR says ...
Coincidently, our CLP315 (310) refused to print any more last month, just got one of those idiot "something is terribly wrong"
fault codes. Having a lot of spare toner, I just bought a couple more 2nd hand units off ebay, cost app $30 EACH !! Made a
Frankenstein out of the new organs, and viola .. enough toner and spares for AGES ! Never found the fault, but for the price,
I didn't care. Maybe it's worth trying too?