I have sent my AKG K 271 MK II headphones for repair at the store. I had to pay around 35$ for the "depot". Finally, it wasn't repaired and I get told that it was not worth repairing because the mecanism is now too fragile since it is broken.
I decided to try to do the job myself and just got them repaired today. It was only a loosen wired needed to be soldered.
$$ in trash. Thanks Steve's music!