I really thought my 7th gen nano headphone jack was a goner. I searched online and found a webpage that offered solutions to find out what the problem is and possibly fix it. What sort of worked for me is the pull off one of the cotton ends of a cotton bud, dip it in a small amount of rubbing alcohol and try to clean any debris out of the headphone jack port. It took a few tries, but now I can get sound out of both sides of the headphones and also via the aux output in my truck. I think it still needs some work as its a little sketchy, but thank God something works!