Pc not showing display

I just built a new pc, and I haven’t even installed windows and I have a issue, I got into bios and left my pc on overnight and everything was fine, I then leave for 10 minutes to walk my dogs. Come back, pc still on monitor off, I turn monitor back on and it says no signal, I have tried different cables, different ports, different monitors. Didn’t work, yes I have turned it on and off again