660 in endless 'Updating GPS Firmware. 1%' loop

[balvord]

Hello sussamb,
I am having the firmware update problem on my 660 and was trying to find out if anybody has found the solution. I've done many attempts at changing the gupdate.gcd file with no luck. Any suggestions welcome. Thanks

Original post:
Hi,
I'm new here and not a very techie rider, hope you guys can help me with an issue I have.
I just updated my Garmin Zumo 660 in Garmin Express. I had some overdue system and maps updates.
Everything seemed to go well during the update process.
But now once I've powered up the GPS there is this message that keeps coming up 'Updating GPS Firmware. 1%'.
And immediately after this other one comes: 'GPS update complete'.
And a few seconds after the whole thing stars again. Endless loop.
Can't do anything with the GPS because it's just focused on this process.
I've done a couple hard resets (the one pushing the lower right corner and the 'on' button) and erased all user data but it still does the same.
I connected the GPS again to Garmin Express and Garmin Express says everything is fine.
I don't know what else to do.
Any help is welcome!

If you can access your device via Windows Explorer then delete gupdate.gcd as that is the update file, and it is probably corrupted. If it then starts normally you can then reinstall the update file.

[sussamb]

If you've been able to delete the gupdate.gcd file, installed a new one using Express and it's still not working then there is nothing else I can suggest other than call Garmin Product Support for help