Xenon lights

One of my headlights is dead (dipped left beam failure). I've tried swapping the bulb and the ignitor without success so I'm guessing that leaves the ballast. Is that correct? Or is it likely something else?
I've also run out of patience swapping bulbs and stuff around so removing the bumper to get at the ballast really isn't appealing. Can anyone recommend a place that will do this for me that won't charge dealership prices? Somewhere near Maynooth is a bonus.

Any signs of dampness in the headlamp as they can suffer with corrosion in the control unit at the bottom of the headlamp

I have the same problem in my 2004 320d my drivers side headlight is getting damp inside and when I have if on it just flickers on and off still comes on but just keeps flickering. And I can't get a headlight anywhere in ireland