If you've never replaced the barrel jack, 20 years a good long stretch. We stopped using them on most new builds because of their short life (usually only 5-10 years). And we sell pre-wired replacements in our online store in sets of 2, so you can have a spare in the case, just in case.
It tends to be the diameter of the connector - many are _slightly_ larger than 1/4", which is very annoying considering they are called 1/4" connectors! But now there's all sorts of strangeness in connectors, and some are weird lengths, contacts at the tip cut way in and miss the contacts on the jack. Things that don't adhere to the standards are kinda common.