Enduro 3 Boot Loop 12.35

Hi,

I installed 12.35 Last Night on my new Garmin and now it is stuck in booting. The triangle appears, after a few seconds it goes away and then appears again. I did try a hard reset but could not get it to work. (The beeps never came as a sign to release the buttons)

I tried those ways:

-hold start light and back at the same time let go of light 

-hold light first, let go then immediately hold back and start.

I never heard a beep. I think there is to little time for the watch to acknowledge there is a hard reset because it seems to boot every 5 seconds.

i tried to connect to PC as well, but the watch is not detected.

please help!