After doing a little research, it seemed the most likely culprit was the high-limit thermostat. I watched the AppliancePartsPros video on replacing this component. It didn't look too hard so I started taking my dryer apart. The inside was full of lint and I found singed lint on the heating element. Figured it got too hot and burned out the thermostat, so I ordered a new one. I also ordered a new OEM lint filter to keep this from happening again. (Hubby had bought a cheap one 2 years back, which didn't fit perfectly and probably caused the problem in the first place!) Cleaned out all the lint, installed the new thermostat, and put it back together. It's like a whole new dryer!