Hey Bill...crack it open sounds too horrible to think about!
I would ensure that all the plug-in's on the board are seated tight. If I remember correctly the Further pickups plug into the filters.
On that note, you could move the pickup plugs around on the different filters, and see if the problem follows the pickup (then the issue is the pickup), or if it stays on the same channel on the harness, which would mean there is a problem with the harness wiring, and not the pickup.
Try that. Ron made his stuff so modular that these should be easy steps. It took me about 15 minutes to completely remove my harness when I had to send it in for repair, and about 15 to put the new one back in. Here's the link to my repair...AND if it IS a filter, I have my extras from the repair and would be glad to send you one.
Easy peasy Japanesy!
Oh and a pic, to remember

I will never forget!
(Message edited by paulman on November 09, 2009)