starts to power on, then after several seconds, it fades to off.

I have a Garmin Oregon 550 GPS. I think maybe it was shorted out when I unplugged it from the Computer when it was starting to load. I decided to change the batteries first, then it wouldn't start up. Then I changed the batteries again but that apparently wasn't the problem, so I plugged it into the Computer via USB, and it did the exact same thing. I'm thinking maybe I should take it apart to see if I can see something burnt inside, although I can't smell anything.