if still present, remove step by step each Dv and DK , TR and Fuser until you see correct serialnumbers.
Maybe 1 DV or DK breaks the serial communication line.
Maybe yellow or bk Dv is faulty
i hate this error, have had 2 cases like this, after mounting from MK kit suddenly C791x.
Also after mounting back from original parts...
Finally we used these systems for trash.
Bookmarks