The "Model Selector" is simply a small four connector in-line plug that has some combination of its connectors fitted with jump wires. Start by unplugging the dryer. Then, on the back of the top display panel, (which you can access by taking the four screws off to remove the top control panel and tilting the back up and slightly towards you), you will notice several connector plugs. As you are facing it, the white plug on the bottom with four (4) in-line holes in it is the Model Selector. First, make sure it is snug and in squarely plugged in. Second, check the continuity between any holes that have a looped wire (a wire going up from one hole and down a second one). Third, clean the connectors. If all of the above is fine, check the heat igniter sensor on the bottom front right of the dryer (you'll have to remove the top and then front of the dryer to access this). the ignitor sensor is towards the front of the dryer. the Model Sensor checks to see if this is in place and functional before allowing the dryer to work. In my case, this was the issue. I simply cleaned it and checked the connections and everything started working again! Good Luck!