My Roper Dryer stopped working , what might I check to see what the problem is.

First make sure you have 220 going to the put the timer on time put your ear up to the timer and see if you hear the timer moter runing.if you do than you have a bad thermal will nead to remove the back panal and the power cord cover.on the lower left you will see a white plastic switch with two blue wires going to it.this is the thwermal switch,if you use a meter and this switch is open than you nead to replace it