I would verify 120vac between the two wires at connector 702 of the inverter when a cycle is started. If you don't have voltage, than something else is causing the problem. If you do have voltage, then the inverter is the likely failure. I say likely just because much like you have found in the tech sheet, when it comes down to a failure of two boards that communicate with each other, we have to pick the most likely of the two because we don't really know if the control board isn't telling the inverter to turn on, or maybe the inverter just isn't listening. But if you eliminate the voltage sources as being the problem, the inverter is your most likely failure.