Firstly what make is it? without knowing the make i cannot be sure. But i will tell you as most tumble driers go that the problem is either due to the element which is very doubtful or most likely a thermostat. Replace both thermostats in pairs once you have ruled out the element.Obvious signs to look for the elements burnt or shorted this will cause the springy elements to drop you will see it straight away.
MAKE SURE THE MAINS ARE DISCONNECTED BEFORE DOING ANY WORK ON YOUR MACHINE. IF IN DOUBT CONTACT AN ENGINEER.
carlito Corway
January 2008