A few years back, I was lucky enough to win an iPod Nano from the Clock Tower Law Group (because I returned a data sheet at the right time). It was pretty cutting-edge at the time and I really enjoyed listening to podcasts on a variety of subjects during morning runs. For about three months. At that point, it was "borrowed" by kit and kin and I've barely used it since. C'est la vie.
My wife, who is studying voice, relied upon the iPod heavily. She listened to music she was studying, new songs, recordings of her voice lessons, and warm-up routines. She would use the iPod to get her voice work in where ever possible; no small challenge while raising five children. So, when the iPod stopped working reliably, she was at a loss.
The symptoms were that the sound was not coming reliably through both headphone ear buds. I tried swapping headphones, listening to different music and as many other diagnostic comparisons as I could manage. I wish I knew how to put the iPod into diagnostic mode then. (Press and hold the center Activate button + the Menu button until the phone reboots. Then move your finger from the Menu button to the Left Arrow button and press and hold the Activate and Left Arrow button until the diagnostic menu appears. Press Activate + Menu to reboot when done).
Nonetheless, I determined that the headphone jack was defective. I despaired at the thought of trying to pry open the iPod and replace the headphone jack, but since the darn thing didn't work anyway, what did I have to loose?
I googled around for a 1st Generation iPod Nano headphone jack and purchased one for $6 from Binh An at firstname.lastname@example.org through eBay. He was very helpful even when I initially purchased the wrong generation headphone jack. I also picked up a replacement battery since I knew I would have the unit open. Mr. Binh included an iPod tool for opening the unit at no cost.
I followed the directions at www.ifixit.com to open the unit and remove the motherboard. The headphone jack is held to the motherboard by a screw and there is a small nipple under the motherboard that fits into a hole in the headphone jack unit. I used a pencil tip on my soldering iron and removed the old headphone jack. I then stripped off as much old solder as possible with some solder braid and cleaned up the entire area by scraping away the solder paste that appeared.
Finally, I put the new headphone jack in place and carefully soldered the four leads to the motherboard. Keep your soldering iron hot and touch the tip to the leads one at a time. Wait a moment before moving to the next lead to let the board cool down.
Then I replaced the battery -- very straight forward compared to soldering the leads of the headphone jack. I used a tiny drop of cryanoacrylate to re-attach the grounding strap before closing up the unit. Make sure the ground strap runs from the headphone jack screw to the back plate.
Check that the little tabs on the metal back plate are all in the proper position before closing up the unit. They're easy to bend when opening the unit.
I charged up the battery and ran the unit through the diagnostics. Everything works perfectly and my wife has her iPod back for less than $20 in materials.