After firmware update does not turn on

Hi All

I plugged in my 700i to my Windows pc and did an update for the latest software with garmin Express.

The unit swiched off and came on for an instant and switced off again

When I power on the red light appears GARMIN writing comes on than fades away and switches off.

Unable to see it as USB device on Windows explorer, or Garmin express.

I have tried to do a hard reset by pressing the power button until red light comes on and than 2 quick press and release the power button.

The green light comes on and the unit powers down again.

Many years ago I had a simular problem with my oregon 550 and Garmin send me couple recovery files and managed to restore it.

Is there such recovery software for the 700i.

Any help will be apprieciated.

Thanks

Vlas