Hi All, my russian muff started playing up so I tried swapping the switch over. I must have had the orientation of the switch wrong as it didn’t work. So I put the old switch back in. I double checked all the wires against pics I took and they are back as they should be but now the pedal just humms a lot even worse when no effect is turned on. What have I done and how can I fix it.

Don’t let this old russian war horse die.