22.10 / Dell G5 SE 5505 / mid-boot powers down

I have a Dell G5 SE 5505 with Radeon 5600M, dual booting Ubuntu. Ubuntu 22.10 / kernel 5.19.0-35-generic now hard powering off mid boot, unless I add 'nomodeset' to Grub, and then I am stuck in software renderer.

Background: I've had battery / power cord / adapter problems since the beginning. The latest of these problems was it would constantly give a warning that the AC voltage was incorrect when the voltage was fine - and with this warning it would massively under-power itself. This is a known issue that most forums say requires a replacement of a part on the motherboard, something I can't do at the moment. I did find some forum posts that suggested the most up-to-date BIOS patches could fix this, and so I regretfully went to Window and installed all the Dell updates I could through Dell SupportRecovery. That didn't help. So last I pulled the battery and am now running it on AC directly, and this seems to work, but now I've run into some new problems.

Now Ubuntu powers off mid-boot. If I add 'nomodeset' then I can boot, but then Ubuntu is then stuck in software renderer.

I have been pulling journalctl logs to look for any possible crash and they seem to cut off at random places. I don't see anything obvious signifying what's going wrong before the power-off.

I tried the Grub argument amdgpu.runpm=0, no luck.

I tried radeon.cik_support= radeon.si_support=0 amdgpu.cik_support=1 amdgpu.si_support=1 amdgpu.dpm=1 amdgpu.dc=1, no luck.

I tried apt-get install --reinstall xserver-xorg-video-amdgpu, no luck.

I tried booting with /etc/modprobe.d/blacklist.conf containing blacklist radeon, no luck.

I still have kernel 5.19.0-26-generic installed, I tried booting into that, no difference.

I tried booting 5.19.0-26-generic using amdgpu.runpm=0, no difference.

I tried booting with GRUB_CMDLINE_LINUX="text", GRUB_TERMINAL="console", systemctl set-default multi-user.target ... it does get to the login prompt, but as soon as I log in it will output info about what packages are available for upgrade ... and then, yes, immediately power off. Edit: Never mind, if I don't log in at prompt then after 10 seconds or so it still powers off. It seems booting in multi-user and console buys me some time, but only nomodeset will save me from the power-off.

Note that when I installed all possible updates through SupportAssist I didn't update the BIOS. The latest G5 SE 5505 BIOS is 1.14.0 but mine is stuck at 1.11.0. I cannot update the BIOS - not through Dell's Windows installer tool, and not through the BIOS F12 boot flash-bios menu. In both cases it complains to me (whether the batter is plugged in or not, whether the AC is plugged in or not) that the battery is too low and therefore it will not let me flash the BIOS. And it won't charge the battery because it can't verify the power adapter is Dell-certified. Because of faulty hardware or firmware.

Ok you can get around the constraints of Dell forcing you to have a battery installed while flashing the BIOS by running from cmd prompt and using "<BIOS flash exe> /forceit", in my case G5_5505_1.14.0.exe /forceit.

This rebooted the system and flashed the BIOS from 1.11.0 to 1.14.0.

It did say "progress 100%" and "Completed" but got stuck on the last screen, no reboot, no response to any keys.

Upon rebooting manually it is now stuck - before even allowing me into BIOS - stuck with a message telling me that the battery needs more than 10% charge to continue. Mind you the battery won't charge, and that is probably to do with Dell's faulty warning that the power source is always bad, and after giving this warning the Dell laptop refuses to charge the battery.

So now I can't even get to BIOS.

Upon further reading it seems it is a faulty Dell detect signal coming from the Dell plugin that is preventing the battery from charging. If I bypass the Dell detect then maybe the battery will charge, and then maybe I can boot into BIOS?

I'm not sure where to go from here.

Any suggestions?

sudo lspci -k | grep -A 3 -E "(VGA|3D)"
07:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Renoir (rev c6)
        Substystem: Dell Renoir
        Kernel modules: amdgpu
07:00.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Renoir Radeon High Definition Audio Controller

sudo lshw -c video
[sudo] password for chris: 
  *-display UNCLAIMED       
       description: Display controller
       product: Navi 10 [Radeon RX 5600 OEM/5600 XT / 5700/5700 XT]
       vendor: Advanced Micro Devices, Inc. [AMD/ATI]
       physical id: 0
       bus info: pci@0000:03:00.0
       version: c2
       width: 64 bits
       clock: 33MHz
       capabilities: pm pciexpress msi cap_list
       configuration: latency=0
       resources: iomemory:fc0-fbf iomemory:fc0-fbf memory:fce0000000-fcefffffff memory:fcf0000000-fcf01fffff memory:d0800000-d087ffff memory:d08a0000-d08bffff
  *-display UNCLAIMED
       description: VGA compatible controller
       product: Renoir
       vendor: Advanced Micro Devices, Inc. [AMD/ATI]
       physical id: 0
       bus info: pci@0000:07:00.0
       version: c6
       width: 64 bits
       clock: 33MHz
       capabilities: pm pciexpress msi msix vga_controller bus_master cap_list
       configuration: latency=0
       resources: iomemory:fc0-fbf iomemory:fc0-fbf memory:fcc0000000-fccfffffff memory:fcd0000000-fcd01fffff ioport:1000(size=256) memory:d0400000-d047ffff
  *-graphics
       product: EFI VGA
       physical id: 2
       logical name: /dev/fb0
       capabilities: fb
       configuration: depth=32 resolution=1920,1080