49 Service Error boot loop

[Navarre]

My printer is stuck in a constant loop, showing "49 Service Error". It restarts, shows the white HP-logo and progress bar, then the blue HP-logo and "Initializing...", then the white "49 Service Error" message and that it needs to be turned off and on again, which it does by itself. This goes on forever.

It started with a "79 Service Error" after a firmware update that I never asked for. After removing a paper jam, the 79-message didn't go away. After a reset to defaults from the printer's menu, the 49-message started and never went away.

I can't use the printer. I can't even access the menu, because the printer never gets ready. I would like to write new firmware to it, but of course that's not possible either. The only thing it responds to, is if I insert a USB-disk that isn't FAT32, but I couldn't find a way to write new firmware from a FAT32 USB-disk. Running a firmware executable downloaded from HP from a computer attached to the printer by an USB-cable didn't work either. It sends the 35 megabytes, buts the printer never noticed.

Please, how can I get this printer to work again?

[Repairatrooper]

As you will see if you look around the forums, this is a common issue. HP is aware of it, is working on a solution, but HP does not offer one yet. The only solution some users have found is to replace the formatter. Timeframe for an HP supplied solution is unknown.