My elite series 2 core controller has a squeak in left trigger. I had same issue before on my last elite series 2.
I sent it in for warranty as i dont wanna hear my controller squeaking every 5 seconds when im playing games.
They have sent back my exact controller and havent fixed the issue it still has the squeak.
So its gone all the way from england to germany put in a different box and just sent straight back to me.
Any way of getting in toucb with someone and getting xbox to actully fix the issuse??