Last 4 cymbal channels are shorting out

[Eric]

Has anyone had a issue with the last 4 channels shorting out? While plugged in, I can wiggle the cord around and get a response. I've resoldered the input stereo jacks but it didn't work. What else could be effecting all four of these channels? I don't know enough about circuit boards to go any further.
Any ideas,
Otherwise, I may have a 6 channel ddrum se for sale.