Headphone port needs fixing

So hey guys,

Im going out an a bit of a stretch here but I was wondering if anyone knows how to fix a small problem I have with my motherboard headphone port. So the deal is that I have my PC underneath my desk, simply because i dont have enough room on my desktop, and I must have bent something when tugging on my headphones. Im using Sennheiser  HD 518s with the 3.5 mm to 6.25 mm adapter and when I let it just hang down I only get the left earcup working. I wiggle it so its a little more horizontal and I get both earcups working. I lift it up so its poinging upwards and I only get the right ear cup working. Is there anything I can use around the home to get this problem straightened out ;) pun intended. The mobo is an AsRock z77 extreme 4.

And to answer the first few questions your're going to throw back at me. Yes it does the same with other headphones. No it does not happen with the front audio port. btw I cant use the front audio because i get so much interference;I can hear all kinds of buzzing and weird noises when I do. No i have not tried resetting the router and no I have not done any overclocking. ;).

ps. Im looking for a dac one day but i dont have an online bank account and I dont intend on getting one. I am looking at the fiio e10 but I dont know where to get it retail in South Australia. Any directions on how I can get my hands on a decent dac would be appreciated, but thats another problem for another day.