I began by checking the thermostatic switches and measuring the resistance of the thermistors with a digital multimeter. When I found that the electronic control board was getting the proper 120 volt input, but was unresponsive, I ordered a new board which arrived in four days. After replacing the board, the dryer came on and I set the model and heater type according to the instructions. Since I hadn't worked on this dryer before, I disassembled it much further than was needed. The next time it goes out, it won't take me nearly as long to troubleshoot it.