Quoted from cody_chunn:Note: The EOS can heat up enough to melt the plastic spacer between switches. This makes it possible to short solenoid voltage into the switch matrix. You can also do it by accident fiddling with it with the power on.
VERY common. As far as I know once this happens you have to buy a whole new stack. I do not think the spacer is available as an individual part (at least it wasn't when mine melted )