M479dw 13.09.04 paper jam, without paper jam

[MaXxiveICT]

Hello all,

My M479dw has something weird. Whenever I give it a print task, it prints the task, then complains about a paperjam in the back of the printer (13.09.04), but there seems to be no paper jam.

When I open up the back and close it again, it prints it again a second time. And then the message disappears.

If I really had a paperjam, would it even print? I got this printer from a friend, who replaced it, while it was still working perfectly. So not sure what's going on here. But when it doesn't get fixed, I can't use the printer. I can work with it, for 1 page. But as soon as I need more pages, it will totally mess the job up.

Please help, I'd love to use the printer for more than just a scan....

[Repairatrooper]

This error indicates a jam in the back door which suggests that the printer may not be detecting the paper when it exits the printer or a flag in the back of the fuser that detects paper exiting the fuser is not working. I have seen a few cases where the optical sensor at the back of the fuser fails and would be the most common cause I have seen of your error. Unfortunately this is not an easily replaced bit and also not sold alone. We typically have harvested sensors from other failed printers. HP would suggest you simply replace the whole fuser assembly. Also a lack of machine level diagnostics for sensors means that this is a have to try it repair and hope for the best. Before taking anything apart, make sure that the fins in the exit bin move properly.