I have had this strat for a while that had previously had troubles with it's grounding as the holes didn't line up with the pickguard causing the pots to touch the shielding in places they weren't supposed to. The problem was resolved until yesterday I got annoyed with the fact that the tremolo was catching on the pickguard. I solved that problem by sanding away a portion of the pickguard by the tremolo. I put the guitar back together and strung it, However it made no sound, I moved the pickguard a millimeter or so and re-screwed it on, solving the problem. It was working fine until it decided to suddenly stop working again. I have located the problem as being the volume pot. When the shaft is pushed away from the pickups the guitar works fine, however when the shaft is secured with the nut it manages to move slightly back causing lack on sound again.

Does anyone have ideas of how to fix this? I've done a fair amount of guitar wiring myself and don't have the money to take it into the shop.
Thank you for your time,