Try clearing the CMOS. Do you get any display output or BIOS/UEFI beeps? If you have a spear CPU (or GPU) lying around try switching them out. Also, if you have duel channel RAM try removing one (Make sure to check the MOBO manual to see what the single channel DIM slot is). If none of this works then you could just wait a bit. Sometimes these issues can be super weird and just happen then after waiting a day they'll go away, its happened to me before hope its as simple as that for you.