Hey Bill,
Here’s a helpful hint for your readers. Customers bring electric guitars into our store all the time complaining that they have lost all their output signal, and often the hum is pretty bad too. Usually the jack is loose and spinning around. When we ask about it, the customer says, “Yeah, it’s been loose for a while and I tried to tighten it but it kept on spinning.” What has happened is that the wrench spun the jack around and the little wires inside the guitar got badly twisted and broke. Presto – no signal. We have to disassemble the guts of the guitar and get out the soldering iron.
The message: If you try to tighten a jack yourself, you’re likely to break off the wires inside your guitar. The better way: Take the jack’s metal mounting plate completely off the guitar, carefully hold the back of the jack so it doesn’t twist, and tighten the nut so the jack is held firmly against the mounting plate. Then reattach the mounting plate to the guitar.
Or even easier: Bring your guitar to a knowledgeable store. We have a special little tool that goes into the jack from the outside and holds it while we tighten the nut. Makes the job simple and quick!
Either way, get a loose jack fixed right away. Those wires are mighty thin and easily broken. You don’t want that to happen in the middle of a gig!
–Carl
Good advice for a common problem. And if you have an input jack on an instrument, amp, or anything else that consistently comes loose, it’s probably missing a lock washer. A good repair shop will know what washers are supposed to be there, and get you fixed up.