My Magellan GPS 9250T-LMB wont come on

My Magellan GPS 9250T-LMB wont come on

I was on the road, my GPS was working. I unplugged the power cord from the car outlet. 5 minutes later, I plugged it back in, but my GPS won't come on. To check if the cord got bad, I checked another cord, but the GPS won't come on. I opened the GPS and checked the voltage of the battery. It shows 3.7 volts. Please tell me your opinion on the problem. Thank you.