Dryer heats but won't turn off
I have a coin operated GE Commercial Dryer Model# DCCD330ED2WC. It heats and drys the clothes well but it does not turn off. Pushing the start button will start the dryer without needing to put quarters into the machine. The timer sets for 45 minutes but when it gets to 1 minute it just continues to run forever until you open the door or unplug it. Unpluging it is the only way to reset the timer back to 45 minutes.
Does anyone know what parts need to be replaced so that the dryer will turn off and will only work if the quarters are put in?