I had a bad power switch in my 450D case. If its not to old corsair will send you a new one. Are you sure the case power and led connectors are on it the correct orientation? Have you tried bios 2 for the hell of it?
If bios 2 still same issue then go back to 1 and press Cmos and power up with one stick of ram in A1see if it starts. Is the keyboard and mouse in the correct spots. There are others on here that will help. Put GPU in the top slot x16#1
Maximus XI Formula, I9-9900k, Phantex Evolove X, Seasonic Titanium 850W, Custom loop PE360+SE360 Rad, G.Skill Trident Z F4-3200C14 32g, Nvidia Reference RTX 2080 TI, Samsung 970 EVO Plus 1Tb, Windows 11