The low G# key on my OP-1, which is not even one month old, no longer works. When pressed it either does nothing, or it seems like it’s shorting (e.g., loose connection). Any advice would be greatly appreciated. I have contacted TE, but haven’t heard back yet. I’m going to call the retailer tomorrow. This is a depressing second post 
Sometimes I press a key and am befuddled as to why there’s no sound until I realize that I still have a sequencer set up that does not start on the first beat. Or I have Punch engaged and set up in a way that I don’t hear anything at all.
Since you’re specifically talking about one key though I’m afraid it’s not that easily fixable…
Yeah, I wish it would have been my error. Anyhow, it all worked out. The retailer exchanged the unit. The key was non-responsive. Weird. Guess it was just a fluke.