My dryer is showing erratic behavior with the lights and starting functions. Most of the time, when turning the dial to choose the drying mode, only Normal mode works. Additionally, after turning the dial from Normal when the panel is on the dryer will start to run without pressing start. The dryer will then not run the full time either and stop early. Diagnostic mode doe not show error codes, but turning the dial to modes other than normal will return erratic behavior. I assume the is a control board issue, but what can I do to verify which board?