I have an Ampeg SVT-6 Pro and my input jack is a bit "loose". (not the jack in the case, but the way it holds the cables.) When I plug certain inst. cables they pull in and out slightly and sometimes the signal is lost (especially if I move around). With other cables it's better, but the cables never really "snap" in. I'd like to open it up and either squeeze the contacts together so they're more snugly gripping the cables, or replace the jack altogether. Is there any danger opening the case? Do I need to watch out for anything storing voltage? What else do I need to know before proceeding? THANKS!!!