Assuming the dryer runs, just doesn't produce heat? Did you test the thermal cutoff? Other than that, looks like a faulty control board. A relay on the control board is used to turn the heat on/off. You could disconnect the red and black wires from the relay, make a PROPER jumper to jump them together and see if the heat works then. If it does, you need a new control board. Only do this for testing, do not try to use the dryer with those wires jumped out.

Eric

You will need to replace the board. The relay is soldered in and we don't know if the relay is the problem or the electronic components that control the relay is the problem. Check for a faulty solder joint where the relay is soldered in. That is a common failure point and you may be able to repair that if it's the problem and there isn't too much damage to the board.

You could put your finger on the relay case and see if you can feel a click when you turn the dryer on. If it clicks, then the electronics are probably ok and you could replace the relay if you have some soldering skills. Just Google search the relay part number to find a replacement.

Eric