Audi a4 b8 headlight issue

[John law]

Good evening I have a Audi 2009 b8 I have a problem with headlights after about 10/20 minutes I lose dip beam one side goes then I lose the other side could any body have a idea what could be causing this problem 

thanks john 

[Steve Q]

I'd recommend a diagnostic check to see if any fault codes flag up. It could be an issue with the ballast.