After changing out the strings, I noticed that the tone control on my Fender American standard jazz bass does not work at all. It may not have been working for quite some time, I never really use the tone control, especially live. The tone control has literally no effect on either/both jbass pickups at any volume or any position on the tone knob. I'm wondering if there may be a bad capacitor to blame or a bad pot, but I have no idea how to tell which one it could be w/out replacing them. Is there any good way to tell? I have a multimeter but have no clue how to check soldered connections w/ it. I should mention that I replaced the electronics about 7 years ago w/ a jazz bass wiring harness curtesy of Butch Ammons at Bayou cables. Also, I recently used copper shielding tape to shield all cavities. All soldering connections seem solid and the tone knob does not work even when the electronics are pulled out of the control cavity, so there is no short circuits going on either. Anyone have any ideas?