Tested the thermal fuse with an ohm meter. The fuse was ok. The next recommended likely failure point was the controller board. I bought the board from Appliance Parts Pros on a Tuesday night and asked for two day shipping so I could have it by Friday, but it arrived on Thursday (one day). The board has the color of the wires to connect embossed on its plastic case. That makes it very easy, although I took pictures of the boards and cables before I removed the board, just in case. When I removed the old board I found that a capacitor was blown as it had split apart. When I plugged the new board in the dishwasher worked correctly. Subsequently I asked Appliance Parts Pros if they had a program to buy back the old controller board for refurbishment, but they don't. They suggested I sell it on eBay or Amazon.