Może to coś pomoże:
Error 12 Printer Open no EP cartridge
Check that the toner cartridge is installed.
Check that the top cover is firmly closed.
On HP IIP/IIP+/IIIP printers the primary cause is the density adjusting PCA. There is a slight possibility of it being a bad fan. There is also a slight possibility of the tab on the fuser access door above the MP tray breaking off and causing the error. If the fan starts to run, quits and you notice a burning odor, the scanner motor has failed and needs to be replaced. The problem can also be caused by a defective drum shutter on the toner cartridge.
A przede wszystkim sprawdź wszystkie czujniki klap i obecności modułu bębna.