IRok won't turn on without PC

I was stupid and didn't bother reading the manual for my iRok AST503. I plugged it into my computer, got the songs onto it, then unplugged it without clicking on the button on the button on the task bar that is supposed to make it so you can safely disconnect the cable. My iRok won't turn on unless I plug it into the computer. I've tried plugging it in and safely disconnecting it, but it still won't turn on without the PC. Have I wrecked my mp3, or is there a way I can fix it?