Vauxhall Vectra headlight main beam not working

When I attempt to switch my headlights to main beam they do not come on. The main beam icon is illuminated on the dash, but no power is getting through to the separate main beam bulbs contained within each headlight unit. Neither intermittent or continuous main beam works. Have had problem checked by my local garage and they say the switch connected to the indicator/main beam control is working, but the power is not getting through to the main beam bulbs and could be due to a fault on the underbonnet electronic control module (UEC)? Any suggestions gratefully received - just wondered if any one has come across this problem before?