I know this is a common problem but The jack on my guitar came loose, i keep trying to tighten it but it dosent work. I tried unscrewing the plate, but I don't really know how to go about tightening it correctly
tighten the nut on the other side of the plate. Normally, the input jack is bolted or fastened to the plate which is then fastened to the body of the guitar. Be careful, though. If you over turn or wrench it, the wiring will pull off.
like said. ^
here's a pic tho.
Clamp the hex nut on the other side of the jack plate ( the part that goes inside the guitar) and tighten gently the one on the outside. That should take care of it. If the Jack is wobbling around in there and the tightness of the nut isn't the issue, then gently bend the contact prong (the part that touches the jackinside the guitar) inwards a slight bit. That will hold it steady against the jack.