We had one of these machines that was tracking as if the cleaning belt was not cleaning. Tech support had us try the 107 set 80. Then when that didn't work replaced hvu 1&2 boards. When that din't work new engine and main pcb's. When that didn't work we finally got someone to have us look at the wire coming off of hvu transfer 1 board. It is the single white wire running to the contact spring for the transfer belt cleaning brush. It is a %#% to get to but we found that the end that goes to the spring block has an eyelet on the end of the wire. This eyelet goes over a plastic post and is held in place by spring pressure. You have to almost completely compress the spring to get it on the post. It was not on the post or even touching the spring. Suprise suprise that was the problem. It had worked for a time on first install so all I can think is that it was inserted into the spring and not on the post from the factory as we were never that deep into the machine. Sorry for the long winded post but if you are having belt cleaning issues check continuity from that wire to the spring. It could save alot of time.

Thanks for the heads up. A new machine delivered mid February has just started to do this. We read the post, checked the connection to find it wasnt making one. Reseated connector on post under the spring and 1x happy customer and 1X very grateful tech.
Thanks again