[BJB]

Does the bulb light up at all, or does it light up,and go out (dash warning) after a couple of minutes?
Had à problem (with latter) myself, changed ballasts, still the same. Made a mistake and bought brand new ballasts (correct units) from a German supplier. What I, and the supplier didn't realise, was that they needed a Volvo pre-programming to fix self levelling out before a Vida final program.
My local Volvo Indy checked it out, and found it was a bulb problem. Refitted my OLD ballasts, and reprogrammed them.
The supplier was great about it, and returned all the money, even though it had been over six months when I bought the First one..

It might be worth changing the bulbs, because they can give you problems after a while, as they aren't like normal bulbs, and rely on an arc to make them work