Model MHWZ600TW02. Any cycle selection, when I press start, the drain motor engages whether there is water in the drum or not. I replaced the drain motor but same problem. If I add water to the drum manually, it drains just fine but never does anything but run the drain motor for about 30 seconds and then ends cycle. no error code. my next step is going to be replacing the control board but they're not cheap. so any insight would be appreciated. thanks, Robert