A few months ago, my Kinesis Advantage2 keyboard stopped working properly. I was able to locate a backup keyboard shortly afterward, but the backup is missing a few keys, so I still wanted to repair my daily driver and return it to use.
I exchanged a series of emails with a Technical Specialist at Kinesis, Mr. Tyler Sullivan, in which we discussed the keyboard's behavior and the scope of the problem. He suggested that the main cable, which connects the keyboard over USB, might be shorting out. He sent me a replacement cable to install.
I wasn't able to get around to this as fast as I wanted, but today was the day. I flipped the keyboard onto its face, unscrewed the back plate, and put the plate aside to expose the circuit board.
[Perhaps this post should have photos, but the process had so few steps that I didn't feel it was worth documenting visually.]
I noticed dust and dirt buildup on the inside of the case, so my first order of business was to wipe away the debris with a microfiber cloth. After the housekeeping was over, I unplugged the main cable from the circuit board, and undid the "E clip" holding the cable inside the case.
With the old cable out of the way, I was free to thread the new cable through the hole in the case. This took a few tries, because I wasn't sure whether feeding it from the outside to the inside, or vice versa, would properly position the cable for securement with the E clip. I think it can be done either way, as long as the biggest of the series of rubber circles on the cable is flush against the outside of the case (which will leave the trench for the E clip just inside the case.)
Re-attach the E clip, test the keyboard to see if it's working -- yes, it is! -- and replace the back plate with its screws. Done!
Now, this tale might not be over: the keyboard was failing intermittently, and it might start going haywire again later in the day. For now, however, it is operating smoothly.
I want to thank Mr. Sullivan for all his help since September. He did a great job explaining what might be going wrong, and walking me through possible quick fixes before sending me the new cable.
[2020-01-02: As I had feared, the keyboard began to malfunction again on the day after I performed this repair. I'll be receiving a replacement motherboard in the mail soon. More hardware jiggery-pokery awaits!]