I installed new pick ups and everything worked. But the next day I would get this ground issue when I would switch between pick ups. There would also be no sound coming from the PUP's. A quick little tap on the control plate anywhere and it would stop, and everything sounded great and worked properly. At that point I realized I would need to have a look. Figured a cold solder joint on the Volume pot grounds. I was away for the weekend so figured I'd play it again for a few minutes when I got home before I pulled it apart to have another look. The ground issue with no sound from PUPS was gone, but it now had no top end. I went staright to the Tone knob to see where it was set. It was up full. I turned it down - no change, turned it up, no change. Before I start resoldering everything, is there an obvious issue based on the symptoms? Thanks.