Although the house circuit breaker is on (disposer works and it is on the same breaker), when the DW is closed and the control is advanced to Start, nothing happens --- no sound, no water fill, etc.
What is the likely problem?
You will want to check the power supply at the base of the unit and make sure that the connection is good. If this checks ok then check the wiring back to the timer. If the wiring checks ok then the timer is faulty and would need to be replaced. Timer part number is WD21X10013.
Control knob stops turning on its own in middle of wash cycle.
You will want to check the heater and thermostat for the unit. Especially if you are using the temp boost option. In this option the unit will pause to heat the water temp and if the water temp is not hot enough coming in or the heater is not working then it will continue to stay in this setting.