I broke the car charger to my gps about a year ago and havent used the gps since. I have a mini usb charger for my computer that I hooked up to my gps to charge it and the green light comes on on the bottom of the device, but it will not come on. It's been charging for about an hour our so, but nothing is happening. Any suggestioins? I've heard that it could take up to 3 hours for it to charge, but if figured it would alteast come on.