Hi, i recently purchased a nextar MA166-200 and when i opened it and installed the software and plugged the mp3 player into my computer and i have been charging it for 4 hours now and when i take it off the usb port and try to turn on the mp3 player it will not turn on but i will turn on if i have it plugged into the usb port. Any suggestions and we have tried the reset button numberous times