I have an MSI B150 M3 motherboard that I am trying to put a computer together for a friend on. The board was previously used on my wife's old computer, still worked just fine when last used. My friend purchased an Intel I5 9400 for it and for some reason the thing will not do anything with this processor on it. If I only plug the board into the power supply and turn it on the board stays on, the red light on the board stays on is how I know. As soon as I install the Processor however it powers off immediately after power is applied.
I have nothing besides the Processor and motherboard powered when I try this, I have also tried it with the graphics card and RAM installed with the same instant off result. Yes both the 8 and 22 pins plugs are connected. I have used two different power supplies, one from my friends old computer and one from my Wife's currently active and working computer.
I have no idea what is going on, please help. Ask me for any missing details.