LoL. I came very close to doing just that today. If I didn't have a softspot for the brand I would have. I'm spoiled on how good this unit sounds. I still have all of my vintage Kenwood from the 90's and wth this HU and it's dedicated processors, once adjusted the sound is just plain awsome.
Anyways, I have two DNN991HDs and I got one of them to work! The second daughterboard did react to the reset somewhat.
The only way I could get these files to boot was to have the longface13 changed to longface14 plus the deletedata and zip folder in a clean USB. It would immediately reboot and no need to wait an hour and no Android image popped up either. took less than three minutes ... I think. The head unit that did not reset properly after a reboot I could only go as far as the PW screen, but not into the main menu. BUT....if I leave the USB inserted and reboot, it will clear the PW screen and go right into the menu like it didn't have a PW but then it reboots again and again and again... until I remove the USB before it reads it again and only then can I use the HU. Once I power off the unit, it will go back to requesting the PW. Frustrating!
It was cool to see them light up again. Is there a remedy for the second unit that failed to clear the PW delete process?
MANY thanks Rad!!