Grub shuts down system, does not even appear

Hey !

So I tried installing a grub theme (matter) (i know it’s stupid) and somehow it completely nuked grub. There’s no grub-rescue, no command line, the pc just shuts down directly after the UEFI if I try to boot through grub.

I’ve been trying a variety of things, obviously I’ve already tried reinstalling grub from a live EndeavourOS usb with chroot (having removed the theme and uninstalled matter), that didn’t work, it kept saying it couldn’t find a grub drive on /dev/sda1 (which is the live usb, my pc has an nvme). When I googled I found like three threads that offered vaguely promising solutions, none of which worked. Meanwhile trying to use grub still resulted into instant shutdown. If I tried to reinstall grub without os-prober it was the exact same.

I tried Super Grub2 which found my Windows but not EndeavourOS. Then I tried Rescatux but that wouldn’t even boot.

Then I had the idea of installing rEFInd, which went a step further and somehow removed my windows boot manager from UEFI (o_O) (now it’s disabled from efibootmgr and it won’t activate, but that’s another issue), all while not fixing my problem at all since when I select EndeavourOS from there, it just tries to use grub which again, shuts down directly.

Finally, I cleaned up my EFI partition and completely removed any trace of grub from my system. Then I reinstalled it the usual way, I no longer got the “couldn’t find a grub drive on /dev/sda1” issue and… It was the exact same. Instant shutdown upon entry.

So yeah, that’s where I’m at after a day of scouring the internet. I have no clue how grub could utterly stop working and be unfixable like that, but admittedly I’m no boot/EFI expert. Has anyone seen this before ? Any idea of what I could try ? Here’s my partitions Feel free to ask for more details. Thanks.

Solved !

I tried a bunch of different things but what ended up working was completely wiping my EFI partition, making it bigger and following this tutorial to set up systemd-boot instead of grub. There were a few boot issues but nothing a good google search couldn’t solve. I still have no idea what happened with grub though… Anyway, now I have to make windows bootable again, but that’s a problem for another day.