Hi,
Was the old switch faulty?
If not, and I know you said that you checked the connections, did you test for continuity from the switch to the control board as well?
With the power disconnected, remove the switch cable from the switch and using an Ohmmeter test between the two wires at the connector socket point back towards the board and see if there is a reading at all. If not identify the switch wires at the control board and prove each one from the switch connector.
Just a thought and if OK or you have done this apologies.