After you’ve finished the guitar setup process, there are a few other things you can do to make sure your guitar is functioning properly. One is to clean out the potentiometers and the output jack.
First, remove the electronics control cavity backplate or pick guard. Then spray out the pots with electronics cleaner to remove dust and debris that might have collected on the carbon wipers (which can lead to a scratchy noise when turning the pots). Remove the knobs and tighten the nuts if the pots are loose on the pick guard or control plate.
On a Gibson-style guitar:
If you’re working on a Gibson-style guitar with pointers underneath the pot nuts, make sure they are all equally facing the same direction. They should be pointing toward the stoptail, before replacing the knobs. Then, tighten the output jack nut if it is loose and clean the output jack with a wire bore cleaning brush.
On a guitar with a jack plate:
On electric guitars with a jack plate, you might have to remove the mounting screws to tighten the jack nut so that the output jack doesn’t twist in place. (This is how a wire can break off of a solder point).
On acoustic guitars with a loose output jack at the end pin, you will want to make sure that the retaining nut inside the guitar is properly adjusted to fit the tail block before tightening the outer nut. To do this, remove the threaded strap button and outer nut and washer, then reach inside the guitar to pull out the jack assembly. Then adjust the inner retaining nut so that the ledge of the output jack sits slightly inside the tail block when installed and re-install the outer nut and threaded strap button. When the fit is nice and tight, you can then screw back on the threaded strap button.
Checking battery strength
At this point, it’s not a bad idea to check battery strength if the guitar has an active pickup or EQ system. It’s much easier to do this with the strings off the guitar on acoustic instruments.