I am also running into this problem intermittently with a pink pair of Barracuda X headphones. The audio in the right ear cup is either completely dead or lower volume, but only sometimes. Giving the right ear-cup a solid few taps, or jostling it a bit (extending and retracting it from the headband) generally resolves the issue. That means it's very likely being caused by some kind of physical connection problems (like a solder joint) coming undone. Since my headset isn't completely hosed, I don't want to take it apart just yet. If you tilt the right earcup downwards and look up towards the headband, you can see a pair of wires running down to each pivot point for the ear cups. It's probably one of these getting disconnected. If you remove the ear cup cushion, it looks like there are four screw holding things in place. The connections can likely be accessed from somewhere behind this. I'll follow up with either a post edit or new entry if I get around to taking this apart and attempting a repair. UPDATE...