Just my two cents worth. I would find the missing voltage to the board before replacing random parts. Verify voltage into the main board on the white connector between pins one and three from the filter board. If you have voltage, then I would suggest removing all the connectors to the main board, except the one from the filter board, and those going to the display board and see if the display comes on. I suspect you have a short somewhere in the unit that is causing the main board to shut down to protect itself. If that works, you can plug each connector back in until you find the one that shuts it off again. If you don't have power when the connectors are removed, the board has failed, and then it would be time to check each component to the main board for a short circuit.
If your wall outlet is wired correctly:1 Blue connects to (White) should be Neutral2 (Green) is Ground3 Brown connects to (Black) is Hot120v between 3 & 1120v between 3 & 2Thanks. I'm not sure what is wrong here. This is the set-up.From wall to plug....Plug into machine into Filter, then Filter into Main Board1 white to blue (filter)2 green to grd 3 black to brown (filter)120V between 1 and 2120V between 2 and 30V between 1 and 3
If your wall outlet is wired correctly:1 Blue connects to (White) should be Neutral2 (Green) is Ground3 Brown connects to (Black) is Hot120v between 3 & 1120v between 3 & 2