STEP 1: Check the master volume level on the mixer. You will find the master level fader on the right. Check this is set to a reasonable level (about 3⁄4 of the way up).
STEP 2: Check the volume level on the channels. If you have plugged in a mic or instrument, check the level knob on your channels is pushed up (about 3⁄4 of the way).
STEP 3: Check the gain level on the channels. Turn up gain knobs slowly. Gain knobs should always be set to 12 o'clock, with volume levels set as recommended in steps 1 and 2.
STEP 4: Check the mic or instrument. If the customer is struggling to get sound from the PA, make sure that the microphone or instrument you are using is on and has the volume level turned up.