Thanks Sam. Yeah, I’ve tried every username/password known to man, nothing works. I was able to load the new firmware, but stupid me, I assumed it would completely overwrite everything (including the current config). Turns out it didn’t so I still had the issue of not actually being able to log in and do anything on the AP.
Luckily, formatting the flash did wipe out the existing config so upon the next boot, everything was back at the out-of-the-box defaults. Now I’m in business.