After a failed firmware update I get the Loader Loading screen of death...

I have tried to

-get into pre-boot screen by pressing top left corner and switching the unit on (on battery power, on mains power, on USB power). no success, it either goes into Loader Loading or 1st goes to the calibration screen Press Dot after which it goes into Loader Loading..
-go a hard reset, press on right bottom corner and do all the variations. No luck
-tried the UPDATER.EXE routine, knowing that I should be in pre-boot. But nothing ventured....
-tried this with various .rgn files. The nuvi shows "Loader" "updating" One even gives me the "loading maps"+status bar on the nivi, but it then falls back into Loader Loading
-at no point can I see the unit in File Explorer..

Since the unit is 2+ years, Garmin is offering me to sell me a new unit for a reduced price. Before I take them up on their kind offer, I'm hoping there is some new insight that has not been posted on the Web just yet....
If I'd dropped the unit and ******* the screen, I would know for sure it was my mistake....

Hope is the last to die...