After removing the switch, check the circuit for a short, and if you have not destroyed the switch , check it. If the switch is the problem, them most likely you have dicsovered the problem. If it is still there , then take out the IC, If you don't have a socket on the IC, I would suggest putting one in. If the short is still there, them most likely either you have a short or a pcb short. Sometimes a PCB short can be taken care of with a voltage on one side and ground on the other. I would start with 5V before going to 12V ,, BUT This is a VERY Last resort, I would try every other method I could think of before doing this. I have had to short a High pin to ground to get an internal short fixed, but this was on some Very old Imsai front Panel connections, but the front panel now Works!!
Thanks Marty