I took apart the control panel, and checked the switches - which turned out to be non-functional. I looked up the part online, found it at AppliancePartsPros.com and ordered it. It showed up a couple days later - and was a snap to replace and reassemble. I had lived for years (literally) with this issue - once I finally decided to tackle it, I probably invested 20 minutes and $50 to solve it. Why didn't I do that sooner?...