How did the process of updating bios go, did it say it was a success? How did you update bios, in the bios itself or Windows?
What happens when you press the power button, does the pc turn on with a black screen or does pc shut down?
Try clear cmos. Shut down pc, disconnect power and discharge remaining capacitor power by holding the power button down for a few seconds. Afterwards short the clear cmos pins, they are located above the F_panel connector. Page 13 in manual, item #18 on motherboard layout. Instructions on how to clear cmos is page 21.
After clearing cmos, try boot. Might want to reseat your ram, trying one stick in A2 slot - second slot from cpu. If successful, go into bios and load optimised defaults, reboot and re-enter bios to reset any other settings you've had prior to bios reset.
If clearing cmos doesn't work, it's possible the bios flash has failed and the backup bios is activated which uses the factory default bios which would be a version below Zen2 support. I'm not sure which version the backup bios is using, hopefully F30 for 200ge to work, should be i hope.
https://www.gigabyte.com/microsite/55/tech_081226_dualbios.htm
Taking your system to a PC store could be an option.