Hi Marius,
I was a contributor to that thread.
I never got anywhere with trying to source my own replacement. The three places I contacted never replied to me.
I ended up sending my unit back to Elektron as it was still under warranty.
Once it’s out of warranty and it happens again I’ll probably just open up my OT and give the fader a good clean. I suspect that what generally happens is that dust/dirt gets on the mechanism because of the open slot.
It might be worth you trying that but obviously only attempt it if you’re confident enough with dismantling the machine. That also may invalidate your warranty so you might want to check with Elektron first if your machine is still within the warranty period.