I have a fridgidaire dryer model # fer231as2 and it won't start.. When I push the start button I get a buzzing sound

That loud buzz could be the motor trying to start. It could be the motor end switch or the motor unless the drum is somehow stuck and will not turn. While you have it apart you might as well check the belt and other wear items.

Here is a lay out with pictures etc for your dryer.

Part Advantage :: Category Search (http://www.partadvantage.com/store/categories/fa/FER231AS2)