Laptop refuses to boot

[MR ZenWiz]

My partner has a Dell Inspiron 17" laptop that decided this morning it
would require a reboot, probably from updates we ran yesterday.

Problem is: it refuses to boot.

It does come up in maintenance mode, but I suspect the disk is
corrupted and I can't force it to fsck the root partition.

The message that comes up is this (as best I can transcribe it from
the photo I took):

[    1.473832] pci 0000:00:00.2: AMD-Vi: Unable to read/write to IOMMU
perf counter.
[    1.5093137] tpm_crb HSFT0101:01: can't request region from
resource [mem 0x4f7/: clean, 202691/5120000 files, 2335516/20479980
blocks
[   11.964891] pciaport 0000:00:01.7 AER:  device [1022:15d3] error
status mask 00000040/00006000
[   11.964896] pciaport 0000:00:01.7: AER:   [6] badTLP
You are in emergency mode. After logging in, type "journalctl -xb" to view
system logs, "systemctl reboot" to reboot, "systemctl default" or "exit"
to boot into default mode.
Press Enter for maintenance.

I did look through the log journalctl presented, but I didn't
recognize any error condition that made any sense to me (and I confess
I detest systemctl and journalctl, and I don't know how to capture
that output to a file I can take elsewhere - would a USB drive work?).

I tried to fsck / but it won't let me (cuh).  I did "touch /forcefsck"
but it failed to get far enough on the reboot to do anything.

I'm currently running the BIOS diagnostics, but there are a couple of
other really annoying interferences as well.

The memory diagnostic it's running is projected to take > 3 hours.  I
don't know what else to do so I'm letting it run.

I tried to boot from my 20.04.1 USB drive - it starts up part way with
really screwed up display attributes (fractured menus laid out in
cascading and overlapping diagonal pieces that don't respond to the
keyboard or mouse) - no hope there.

I tried to boot from both my old 18.04.1 DVD and a newly burned 18.04
(not sure which sub-version, but it's up on the Xubuntu mirrors) and
neither one actually booted all the way up.  I got the "Try
Xubuntu..." prompt from grub and selected that, and five to ten
minutes later the screen was still blank.  I tried unplugging the HDMI
second monitor in case that was the problem, no help there either.  I
plugged it back in - still nothing.

There was a brief flash message on the screen, but it went away too
fast to read or capture - I think it was the same as the first two
lines I transcribed above.

I'm stumped.  I was hoping to run gparted from the Xubuntu
installation live boot - no go.

I can try to dig up (or re-burn) the gparted boot CD, but I'm running
out of hope and I've lost over 90 minutes on this PoS so far.

Any suggestions?  My partner really needs that computer back up again.

FTR, the Windows boot on the laptop works just fine, though, as usual,
it's deathly slow in response time, and all her files are on the Linux
partitions Win 10 can't see (hasn't been updated recently - I can do
that, too, but I hate to depend on anything Windows).

Thanks in advance.

Mark