I had a bulb go out on my 06 330i and verified bad bulb by swapping bulbs right to left. So I did a stupid thing and ordered some cheap Chinese D1S bulbs from eBay and installed them only to find out that nothing worked at all. Putting my old bulb (the one good one) back only reinforced my fear that I'd done some bad damage to the ballasts. Searches here and other forums confirmed my fears. I found out the hard way that BMW ballasts aren't very tolerant of cheap bulbs.
Anyway, I've removed the old ballasts and could immediately smell that rancid odor that they mix with the smoke they compress into chips. Since they were obviously fried, I couldn't resist the temptation to cut one open. It appears that a discreet component (probably a filter capacitor) decided to let its smoke out (click on image for hi res):
Ballast on headlight:
Inside the headlight bucket side of ballast:
So it seems that I can pay $477 each for these, or attempt a repair with a $0.05 capacitor. The only problem is that since it's fried itself into oblivion, I have no idea what the value might be.
Does anyone have a clue? Does anyone have a bad ballast with that component intact that could pop it open to see what value is printed on it?