Ipod nano 5th generation will not turn on!!!!

hi, i've had this problem before, and i held down the menu and center button together for about 10 seconds and it worked like magic! now it did it again...but it's been awhile. my ipod needed to charge since the battery was low, so i plugged it in to the usb adaptor on my computer. now it no longer will turn on. black screen..nothing. so i've looked up multiple ways to fix it and i've tried but it just isn't working. please help me if you can.. thank you.