All right, I've searched and searched to try and work my way out of the pickle I got myself into, but cannot find anything. So, I humbly ask for help here...

Garmin Zumo 660, was completely updated to SW 4.80

It was an OEM model with a motorcycle manufacturer splash screen. I got sick of the screen, and wanted to get rid of it, so I ventured into the world of RGN_Tool and GIR_Editor.

Thought I had everything set up, made the RGN file with the new logo.bin merged into it, deleted any GUPDATE.gcd file on the unit and flashed it through updater.exe. All looked good, until it was clear I was in a boot loop. Would update software 'til about 12%, then try and update again to 100%. Then "boot loader" appeared on the screen and it would start all over.

Made a cure rgn with version 4.80, however, I couldn't get the unit into "pre-boot" mode. Flashed it anyway, and this is where things really went bad. Now the Garmin slash screen comes on for about 3 seconds and the unit powers off.

If I attach it via USB, I can see mass storage mode. And update everything through Webupdater, but updater.exe is not seeing any USB devices attached to the computer. It is quite bizarre.

Couple of questions.

  • Is there anyway to just wipe the firmware clean and start from scratch?
  • Does anyone know how to get this unit into "pre-boot"? Tried holding down the power button, and nothing happened. This was the case before the flashing nightmare, and I can't get another GOOD Zumo 660 into pre-boot either (I have access to a friends).


One more bizarre thing, tried two USB cables, and two different computers, and I can't get updater.exe to recognize the bad unit, or the good unit, either.

Thanks for any help you can offer.