Step two would now be to reset project and scene and make a Master Reset for routing. This will guarantee that the mixer works as supposed (aux mixes are set to prefade 1). Now plug in a microphone in channel 1, select the channel on Main level and raise gain to 30 dB. Then select Aux 1, raise fader 1 to unity and raise the Master fader for aux 1 to -30 dB (not full in order to prevent feedback!). When the monitor is powered on and the volume raised, you should hear something now.