First, try clearing the CMOS settings memory. If you can get into setup after rebooting, use default CMOS settings.
If that doesn’t work, you can try flashing the BIOS memory using tools that can be run without windows from Gigabyte support website.
Just in case it’s some other hardware, use a minimum of memory by removing RAM to only 1 slot. If it doesn’t work, swap with another RAM and see if that works.