The dryer was given to me because it did not work. I took it because I knew ours was 20 years old, and not working very well. I brought the dryer home, and diagnosed the problem with my voltmeter. (I hadn't even taken it out of my truck!) Since our dryer was still working at the time, I stored it until ours finally gave out. Then it was just a matter of buying the part to fix it. But I screwed up. The part that it needed had gone up in price, from the time I got it, to the time I needed it. Dummy me!
The most valueble item needed to fix any appliance, is a digital voltmeter, with continuity tester. They're cheap, and takes a lot of the quesswork out of the job.