Headlight malfunction

[Spiller2001]

Hi guys I know it not a vw but I have audi a1 66 plate I bought the car last year before I bought the car the left headlight there was an issue which they repaired it was ballast costing 410 after 3 months i had the same warning light come up head light malfunction dipped beam, so scanned it with obd2 nothing came up so we bought a cheap ballast for 25 and it worked then failed after 2 days so as the orginal part was from audi we put that back in the car and it worked perfect which is weird as it had failed it worked fine for 5 months solid and tonight it decides to fail has any one experience this?

I replaced the bulb too still same also also done a check on the other headlight to make sure if not electrical but nope that worked perfect it a total mystery...I'm trying to look solutions as I can't think what it could be I mean every post I looked at they said they taken cars to audi and they don't see a problem or they say it the ballast if it the ballast it failed twice the part is under warranty for 2 years and I think if I take it there and they put a new one what saying that won't fail too...

If any one can suggest or had this experience and fixed it I would love to know...

So here what we done so far

Scanned for codes and run test on obd2
No errors

Check fuses all fine

It has new ballast

Check wiring all looks fine

New xenon bulb

[Sid2020]

How have you fixed this.

you could swop ballast and bulb from side to side and see if the fault moves with them or remains in the same headlamp. If the fault remains in the same headlamp then it narrows it down either a wiring fault inside the headlight which could be checked easily, failing that it could be a signal fault from the cars module to the headlamp which would require tracing wires from plug to module