New dishwasher fills with water but does not start...

It is possible that the motor pump seal is locked and needs to be freed up. Remove the filter and sump screen and place an 8mm nut driver or socket into the circulation pump opening ont eh right hand side. The nut driver will engage a nut on the center of the circulation pump impeller rotate it 2 revolutions clockwise to free it up. If it does not turn at all then the motor needs to be replaced. Remove the nut driver replace the screens and check for operation.