I went to plug up my ipod nano third generation

Try reseting it, It worked for me. Hold down the "Menu" button and the middle button for about 7-8 seconds.
Hope this helps!

Last Modified: January 28, 2009
Article: HT1320
Old Article: 61705
Summary
Learn how to reset or restart iPod following a freeze.
Toggle the Hold switch on and off. (Slide it to Hold, then turn it off again.)
Press and hold the Menu and Center (Select) buttons simultaneously until the Apple logo appears, about 6 to 8 seconds. You may need to repeat this step.
Tip: If you are having difficulty resetting your iPod, set it on a flat surface. Make sure the finger pressing the Select button is not touching any part of the click wheel. Also make sure that you are pressing the Menu button toward the outside of the click wheel, and not near the center.
If the above steps did not work, try connecting iPod to a power adapter and plug the power adapter into an electrical outlet, or connect iPod to your computer. Make sure the computer is turned on and isn't set to go to sleep.

If you are still unable to reset your iPod, use only one finger from one hand to press the Center (Select) button, and one finger from the other hand to press the Menu button.
When you reset iPod all your music and files are saved, but some customized settings may be lost. Date and time are preserved (unless the iPod reset itself because it had no power and then was reconnected to power). Other customized settings, such as Bookmarks, On-The-Go Playlists, Shuffle, Backlight timer, and so forth are preserved from the last time the hard drive turned on.


Please let me know if this does not resolve your issue

Try doing this: Toggle the hold switch and put it back in the off position. Then press and hold the center button and the menu button simultaneously for ten seconds and the apple symbol should come up on the screen. Then it should work like normal. Hope this helps!