Resurrecting this thread because a friend just had a similar issue. Pulled out the switch matrix chart and walked him through checking the other switches that use the same wire feeds as the trough switches.
He found the white/orange one on the blue drop target had broken solder. Close enough to connect and complete the circuit from vibration that it would work intermittently as he first described the problem. Reconnected the wire at the drop target and the trough issues went away.