Wont turn on
Did you try charging it with the USB cord or do you have an adapter that plugs into the wall? If you tried with the USB cord, how long did you let it charge?Did you plug cord directly into computer or do you have external USB hub?Many times the hubs will not have sufficient power to charge.Was your computer"go to sleep"after a while.The ipod will only charge while the computer is awake.
There are a variety of things that could be wrong. If the Ipod sat for a long time the battery could be completely discharged. I've not had this problem on the Nano, but on an old Ipod Mini my sister has. I've noticed that sometimes I need to plug it in with a wall adapter to get the battery charged enough to start up quickly. If the battery is completely discharged,it can take 30 minutes or longer to see any life from the ipod. I would let it charge for few hours if you can then try the reset.
Forgive me for asking this next question...lots of times I ask these basic question and people get mad, but the key lock is off, right? On my Nano there's a small slider switch on the top. In one position the controls are all locked. Please verify that you've got it set to the right position. Mine is locked when I can see the red dot.
Assuming the battery is not totally shot and the key lock is off, it's also possible that it's just "locked up". To reset the Nano press and hold both Menu and Select (center button) for about 5 or 10 seconds. If the Ipod is alive this will reset it.
From your post, I'm not sure if you mean the Ipod was sitting for a long time without being used. If that's the case and it used to work, and it has not gotten wet or anything, then the most likely problem is a bad battery. There are services on the web you can find who will replace the battery for a fee. If, on the other hand, it just suddenly stopped working and the reset does not help you may have a more serious problem. Unfortunately there's no way to tell.
Hope this may help you;
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