Please elaborate on what you have tried.  Initially, you had a PS/2
keyboard plugged into USB-adapter, and that combination went bad
somehow.  Then you tried "A replacement keyboard and adapter."  I'm
confused if you mean that you tried another PS/2 keyboard + USB adapter
combination, or have you tried an actual USB keyboard?  If you've not
tried a USB keyboard yet, do that next, it would be much cheaper than a
motherboard!  Also, you tried a different USB port, but is that port on
the same root hub?  If you haven't yet, try a known-good port (the one
the working mouse is in?).  I'm guessing this newer hardware doesn't
have a PS/2 port?  They are getting more and more rare, but they can
still be found.

Haines Brown wrote:
> Substituted keyboard and cable; pulled all other USB devices.
>
> Hardware is quite new.
>
> Hate to think I may have to replace the motherboard.
>
>
> On Wed, 14 Dec 2022 06:22:30 -0500
> Haines Brown <haines@???> wrote:
>
>>> I went to replug my PS2
>>> keyboard and the PS2-USB adpater separated.
>>>
>>> A replacement keyboard and adapter in different USB port do not work.
>>>
>>>