First I tried replacing the control board on the bottom of the unit. But that did not fix the issue. I also noticed that the LED power indicator on the control board was lighting up fine... so that should probably have tipped me off initially that the control board was not the issue. After a little more research, I decided to try the user interface board at the top of the machine. This board was a bit more of a pain to access, but machine started right up and has been working well since replacement.