loop reboot

Try turning it off completely and open Garmin express in your computer(be aware of the issues with Garmin express deleting your activity history). Leave it charging for a few minutes and then turn it back on and do a sync with express when express detects the watch

I would say it could be good to install any software update available.

Hope this helps 

Thanks, but Garmin express don't have time to sync, fenix crash before...

Connect it to the computer and you should be able to turn the watch off by holding light button. Keep holding the button even when it goes inmediately to reboot loop. Maybe it takes longer than usual, so keep holding the button, but hopefully it will come out of the reboot loop if it's off for a few minutes. 

Contact garmin support if you haven't done it yet. 

I tried...no way...I'm very sad...

I've tried to join garmin support, but no calls and chat Saturdays...

Sorry...

For curiosity, What firmware versión was the watch running? And how did it go to that state? 

Version 8.21

I try to transfert a map with windows explorer

Try turning it off by holding the light and stop/start button. Then plug into external power. It should boot in about 30 seconds. Leave it on external power until you get past the spin animation on the fenix 7 screen. 

I had a similar experience with a garmin explorer route. If you do a search, you will find a post where I mentioned that the watch was crashing and rebooting when I was trying to navigate an explore route. No one responded, so I assume it was a one-off. It seems to be very ramdomly, however I believe some units doesn't handle very well imported tracks somehow.

Try to drain the battery of the watch completely.  don't know if you're doing what I suggested, but are you holding the light button for a minute or more and not releasing it even if it reboots?

Don't works...thanks...