Has my Xenon ballast gone pop?

Driving down the motorway the other day the bulb warning light popped up. On further investigation my passenger side Xenon appeared to have blown.

Today I finally got around to swapping the bulbs around to check and lo and behold both the driver side and passenger side bulbs will light up when fitted into the driver side light but not the other way round. It's definitely not the bulb.

I had some damage to the headlight a few months ago which resulted in the top bracket being broken but until this week it's been fine.

I've checked every fuse that I can find which relates to the lights (both under bonnet and in the dashboard) so this is leading me to believe that something has given up the ghost in the headlight - itself maybe the ballast?

Has anyone else had a similar situation?