Can't access BIOS

I’m trying to do BIOS updates (Framework_Laptop_13_11th_Gen_Intel_Core_BIOS_3.23_3.24_EFI) using a FAT USB stick, but I the machine seems to hang if I press the suggested function keys.

I’m doing this in preparation for installation of a replacement battery.

I’m following this guide, using the UEFI Shell update method.

When booting I’ve tried pressing F12, fn+F12, and also F2 and fn+F2.

I’ve done this with and without inserting the FAT-formatted USB stick with the update.

I’ve also tried setting “fn lock” via the OS.

I’m unable to get into the BIOS.

When I boot the machine without pressing any keys, it starts the OS OK.

If I press F12 or F2 on boot, it hangs. After a few seconds it flashes the diagnostic blink codes. All of the first 12 are green.

Is there anything else I should try?

Other info:

  • Framework Laptop 13 11th Gen Intel
  • OS: Linux, Ubuntu 24.04.4

Edit:

I’ve just tried to use sudo systemctl reboot --firmware-setup but the result is it boots to a black screen and hangs.