Garmin C340 GPS - Will Not Power On

I bouhgt a refurbished Garmin C340 GPS system. It's 2 days old and will not power on. It would not power on out fo the box. When I snapped the C340 into its cradle whioch was plugged inot my car's cigarrette lighter socket it worked immediately. And it worked fairly well - it did take about 10 minutes to locate satellites. But it worked slick. I used it for about 30 minutes and stopped at a store. I was in the store for about 50 minutes. When I came out the C340 would not power up. I took off the face plate and hit the reset button, it still will not power up. I have connected it to my PC, but sicne it won't power on the Windows XP software doesn't know what the device is and stops the loading of my Garmin GPS driver diskette. So the unit appears dead. Is there anything I can do or should I just return it and buy a Magellan?