S4 phone out defective contact and fader issues.

So I've had my s4 for about 7 months now, and I've taken great care of it.
But still somehow the phone out got a defective contact and only the right headphone is working and sometimes the faders (c&d) start going down by themselves when I put em to max. Why is this happening, can I do anything to fix it?
This is really frustrating, if anyone can provide some help it would be greatly appreciated.

thanks in advance.

update, I was kinda pissed and mixed some vinyl and let the s4 turned off. After I while I gave the s4 another go and somehow the phoneout and faders are magically fixed. Now this is happening the second time, not that I'm ungrateful that it's workin again but why does this happen?! All of a sudden the left headphone stopped working, I tried restarting the s4, software.. nothing. Then I turn it of for an hour and it works again. weird.