case scenarios:
1/ switch off the electricity supply + after +-30sec reset to default(clear cmos)+ on & check
2/ flash bios by Q-Flash_Plus + 1/
3/ switch off the electricity supply + take out the battery + on & check
...🤔
what microcode for 1 start(on X7p) vs XOC bios with no problem? https://community.hwbot.org/topic/223144-gigabyte-z790-aorus-tachyon/?do=findComment&comment=651629
disable E-core or Gaming Profile on in bios to flash or test this X7p by Q-Flash_Plus
&after 1'st start + save&exit on 2'nd start you can Gaming Profile off = another choice