Thanks Butters,
my problem is Dezl 760....when i press power button or connect to my laptop with usb always the same....Show Garmin logo...show dezl 7xx copyright 2016 and Loading Maps....and again the same....go into loop. I have no any signal in my laptop (cant see or detect anything). I try to press left upper corner to try preboot but nothing happens. I got this navi like this so i know nothing what was before and why stop to work. Sorry for my bad english