I did read the instructions and even the customer read them out too in case I missed anything obvious. He tried to adjust the thing himself later in the day but the red screws didn't seem to do anything. I did return and fit a replacement and by mutual agreement left the screws alone to see how the factory settings would fair. I've not had any phone calls!! I will give the customer ( friends of mine ) a courtesy call anyway.Did you read the instructions? I think it was the right hand side dial all the way in one direction or the other. May be wrong.