The bulb type is given above (D2S). My right projector went out, about 6 months back. Was convinced that it's the fuse somehow. And sure enough it was. Could be that water seeped through to yours - especially from the ballast gap, if any?
By the way, I upgraded to facelift headlights which have slightly different ballasts to pre-facelift ones. So my pre-facelift ones (ballasts and bulbs and all) are still lying with me