so, we bought some used equipment and one of the color copiers (Ricoh) came in without any PCU's in it. being familiar with the mods and all that i figured it would be no big deal to put the printer (SP C811) units in it. after a couple of mods to the front covers (post/tab thing in a different position prevents it from fitting in the slot [clip it off]), i fired it up and it said there were no PCU's in it...long story short it seems to be related to the TD sensor. i had one used copier drum unit so i replaced piece by piece the drum side, wire harnesses, connector etc. until the sensor was the last thing i changed and voila! it worked...but i didn't have 3 more sensors available so...i poked around the service mode until i turned off "new PCU detection" and they all worked. i've only done this to one machine and when it reached a "low toner" condition it wouldn't recover from we swapped the PCU's out for the copier models...but the printer units came back here and are working in another machine in house...So, anybody have any experience with this? is the toner detection going to be a problem? is there a better workaround? thanks for any and all responses!