HS-DH2.0TGL won't respond

[NitroPress]

Longtime backup unit, have replaced more than one drive over the years, quit in an odd way. I switched to a newer backup unit (a TS2, which I've successfully upgraded in disc size). I'd like to recover this unit if I can. No concern for the data; I can do any clean-slate fix.

However, it's failing to responded to either the browser or firmware updater. Here's what I've got:

• HS-DH2.0TGL, currently identifying to NASnav and on LCD as HS-DHTGL-EM91E.
• Boots to emergency mode by itself.
• Boots to emergency mode if I force it to.
• Shows rotation of info on LCD screen.
• Shows up in NASnav.
• Browser seems to respond at first, then says "Unable to Connect."
• Updater hs-dhtgl-up_214_102 finds and identifies the unit, but clicking Update produces "Couldn't confirm a response from..."

I should note that all these processes, including firmware update, just worked in the last 24 hours with its replacement system at the same IP address. (I have the good one switched out of the network for now.) So it's unlikely to be network connectivity, security, etc. The unit appears to be up and running in EM, and most of the tools can find it but not communicate successfully.

What's the next step?

[NitroPress]

*Bump.*

Any suggestions? For one thing, I can't find a single reference to that unit ID ("HS-DHTGL-EM91E") and wonder how my unit could be mostly-functional and throw out such a strange identifier.

Thanks...