I continue to have problems with the PCU's on the Ricoh Aficio MP171, 161 and 1515 failing early. It seems like the developing unit is over full of toner and it spills over into the gears that drive the dev unit agitators. The developer then wears out the gears and it locks the machine up causing the main motor code SC 500.
I switched from aftermarket to OEM toner and it seemed to help. But I'm still having these PCUs fail prematurely even with OEM toner. I always initialize the developer when I install the new drums and I made sure that all other settings were still at the factory defaults. I wonder if there is some adjustment to the toner replenishing system I might do to increase the life of the PCU?