AT-GS950 config won't factory reset?

Hi /r/networking,
I'm having some trouble. I'm the sole admin at a little government correctional facility, and I've got a network set up for offenders to access the internet on a couple of PCs. I'm expanding their network to a few more PCs in another part of the building. I've got dedicated fiber run between the MDF and the IDF on the other side of the building, for their network, to keep their traffic segregated from the production environment. To make use of the fiber, I've acquired two older switches with SFP connections. They're everyone's favorite: Allied Telesis. They're two identical GS950/8 models, not the most recent edition; none of the eco-friendly mode options or whatever. They've been sitting in a closet here for a couple years, and were apparently working when they were pulled out.

I reset one of them, accessed it at default IP, logged in with the default user and password, ("manager" and "friend") set the new static, and changed the credentials. No problem.
I performed a reset on the second one and was able to get to the default IP over http, but try as I might, I cannot get logged in to the piece of junk. I've tried every combination of default passwords I've ever seen for network devices. I've reset it about 6 times now, every way imaginable. I've scoured search results looking for another set of credentials that would work. Out of desperation, I've tried all of the old credentials that it might have had from the previous sysadmin here. (Which makes 0% sense, since it did do a reset, because the IP changed.) Nothing. I'm at a loss.

I might just have to face the fact that this thing is probably 8 or 10 years old and get some new hardware, but I thought I'd at least make a post here seeking help, as a last ditch effort to avoid another trip to the director's office.
Please, if anyone has any ideas, I'd love to hear them.
Thanks.

Edit: And no, there doesn't appear to be any way to connect to a console/shell/CLI, unless I'm missing something. But I'd probably have the same issue, even if I could.