I've tried to look for a better thread title but I literally have no idea what is going on with my bass, a Cort Artisan B5 with Bartolini pre/pickups. It was bought used so I can't say what year is it. Definitely pre-2015. When I plug the jack in it doesn't make any sound. I've changed the battery with three different brands but nothing changes. Sometimes, when I rattle it hard, it makes some static/clip sound but I haven't found anything in the electronics that could reproduce it. Could it be a bad 9V battery clip? When this problem started if I rattled the battery it used to work, but now it doesn't make any difference. I have a cheap multimeter but I have no idea how to use it (it was bundled with something else).