Not sure of the part number cuz I no longer have my rsx 850, I traded and went back to an 825. I think it costs $50, mine broke and had to be replaced. I did it myself. It was tough with my large hands and it would have helped if I would have had three hands but I got it done. One thing to know because I thought they had given me the wrong cable because it was twice as long as my old one but the newer cable is different. But they printed out instructions for me which tells how to route it. I guess they had so many break they had to redesign it. Good luck.