ottovonsanders :
Just replaced Cpu And the same thing happens I’m not really sure what’s going on and if the board was the Issue then why is 24 pin plug powering on everything on the board I’m not really sure what’s going on I have replaced CPU but I kept the same stock fan maybe I should switch it with a new fan to see if that works. I wonder if the second power supply I have is faulty somehow I wish there was a way to test out this mobo but I don’t have another 300 series motherboard lying around so not really sure what to do here
If this is a new build that hasn't been running before, it would seem the board is indeed the culprit. Not all that unusual to have a defective board. I've had my share.
Try splitting the 4+4 connector and just powering
half of the 8-pin header. Then
just the other half.
Lastly, try this. Remove the board and breadboard the system on an insulated surface. Connect just the CPU/cooler, monitor (iGPU), RAM, PSU. No KB or mouse or any other components. Start the system by momentarily shorting the two pins that the case's power button would connect to. See if it starts and produces a display.