I use the toothpick with the phone closed. I'd suggest using a sharp toothpick and not a paper clip or something because a toothpick has a little bit of give and is less likely to tear or majorly bend the contacts. Again do this at your own risk, I'm not stating that it's a fix but it has kept mine going. One thing to note is that my headphone jack has always worked with headphones, it's just the internal speakers & mic that would go out, so if your headphones are not working then you may have pulled the jack away from the board completely. I wasn't sure what you meant by "cant listen to music anymore". If you're just talking about not using the jack once you have it working to keep it from breaking again then ignore the last comment. I've been leary to use mine since I got it working.
Up until last friday I was running the stock ROMs only. Can't say that anymore
It's not too hard to take the phone apart but I was a bit worried the first time I did it. I'm posting this from memory so you may want too look up the disassembly instructions before trying it. But basically you take out the battery, remove the 2 screws in the battery case carfully pry up the top cover (where the camera is), remove the screw holding down the wifi antenna (don't remove the antenna), remove one screw from the board w/ the camera flash and remove that board, remove the camera itself (both just pop out of their sockets), remove the screws from the back casing and carfully pry it off working around the edges, don't just yank it up from one corner or side, remove the screws holding in the main motherboard, pop off the ribbon connector in the lower left hand corner. Underneath the motherboard is another ribbon cable taped to it, carefully remove the tape from the board and disconnect the ribbon cable from it's socket. You can now remove the main board. The headphone jack is on the main board so this is as far as you need to go. There is a good set of disassembly instructions here:
http://pdaphonehome.com/forums/ppc-6...bly-guide.html Stop at step 8.
When working on the headphone jack the microphone is fairly close so getting a soldering iron in there can be tight but the black piece on the microphone is just an accustical hood that just pops off giving you more room. Each time I've taken the board out it has pulled the headphone jack away from the board a bit due to angling it out of the case but it hasn't broken any solder points or anything so I'm not certain whether the headphone jack itself can come apart, I may test that out if I have to take it apart again. You should be able to see how the jack works fairly easily from this point. The contacts I have problems with are the ones closest to the mic. This is where the one leaf is soldered straight to the board. The first time I took it apart I resoldered all all the solder points but I don't think this was nessisary and it didn't fix anything. The other two times I simply manipulated the contacts using a sewing needle. My phone is still not perfect and still goes out periodically but it normally just takes blowing into the headphone jack to get it to work now whereas when I first took it apart I couldn't get it to work at all no matter what I did. The toothpick trick was used between then and now. I haven't had to use a toothpick since the last time I took it apart.
Hope this helps.