Hi... believe me, I've searched long and hard for answers, even went to a tech to try to get it fixed to no avail, and I'm convinced now that it cannot be solved. Basically, the '96 Thunderbird alternates between a loud steady hum (regardless of whether my hands are on the strings) to a massive, thundering buzz (triggered by either movement in my cable or my hands on the strings). This did not start until earlier this year, and I haven't been able to play it since then. I don't believe that a bass can all of a sudden become not properly grounded when it was working just fine before. I've checked all the joints for cold solder. I've installed a brand new jack. I've even shielded both pick-up cavities. Nothing works. Any advice?