Quote Originally Posted by giddyupngo View Post
I just had one of these today with the message "replace process unit". It just means the U251 Maintenance count has broken 100K. I just reset the U251 counter to zero, and the message disappears. Since these are all out of warranty, and typically you would replace drums and developers only as needed, it would be a good idea to check the U251 count on each visit to keep it under 100K. Otherwise you will end up with extra service calls. I did empty out the toner in the drum, there are two squarish panels on the end opposite the handles that pop out. The drum was replaced in my case only 20K ago.
Also, to piggyback on this thought of resetting counts, you CAN empty the waste out, however if you wait until it is full, the cleaning blade will be fouled and you have to replace it anyways. Its all contingent on PQ, obviously, If the PM count is reset when drums are replaced, you will see that the cycles tend to match up, its typically when someone changes out the drum for a pq or noise, etc that the counts get out of sync.