A new ballast solved the problem. However, since I wasn't too keen on paying the Porsche tax, I found a replacement on Amazon. The difference was that it didn't have the screw holes for mounting it to the headlight casing. But for a fraction of the price (I'm talking 1/20th!!!) it was worth a chance. It turned out to not only work, but I could also swap the electronics into the old casing with the screw holes. That's a win!
