Troubleshooting hardware problems

Memory (RAM)

• The Gentoo packages memtest86 and memtest86+ provide tests for the memory in your computer. However, there is no way to run these programs from a running system. They must be ran from a special bootloader: the Gentoo packages basically install that bootloader and add an option to GRUB to start the tests.

Nvidia GPUs

• I had a case where an nvidia card HDMI output would no longer work (black monitor), even during power-up and bringing up UEFI / BIOS interface. Booting into Windows (using the built-in Intel HD HDMI output from the motherboard) and then switching the HDMI cable to the nvidia card "resurrected" the card. Windows output was even working instantly without a reboot.

EVGA nVidia GeForce RTX 3080 Ti

• The card works, but produces a blank screen at boot (during POST/UEFI BIOS). The screen only starts after Linux (or Windows) has booted. This makes it very difficult to access the BIOS or the GRUB dual bootloader.
• Tried to update motherboard BIOS, GPU VBIOS and firmware without any improvement.