Case fans and MOBO led stay on/turn on by themselves when PC is turned off, won’t post

[johnsoner13]

So I just received a new motherboard and cpu to upgrade my current rig as I've been getting a cpu bottleneck in some games. However, after installing everything and replacing the cpu and motherboard, when I plugged in the power cable the case fans started to spin and an LED (Red led next to where it says “CPU”) on the motherboard lit up. I didnt turn on the PC, only plugged in the power cable. Also, it doesn't usually give my monitor a signal, but sometimes it does and I can get into bios, and i can see it detects my cpu properly, but when I try to get past the bios i lose the signal, and then after rebooting I can't even get into the bios again. I switched back to my old motherboard and cpu and everything worked fine, so I'm just assuming something's wrong with my motherboard? I've checked for bent pins on my cpu, but it looks fine overall, although on the motherboard there’s a solid red LED next to “CPU”. I'm pretty new to PC building and I'm hoping I didn't mess anything up really and the motherboard was just DOA, or hoping that flashing bios or something of the sort can help, im very desperate. PSU is around 600-650 watts gold rated, dont remember exact wattage but it should be enough for my upgrade right?
Current working rig- i5 6500 | GTX 1060 6GB | MSI Z170A Krait Gaming 3x motherboard
Not working rig- Ryzen 5 2600 | GTX 1060 6GB | MSI B450 Tomahawk MAX

[Lendier]

1. Red LED with "CPU" label next to it is one of 4 diagnostic LEDs (3 other are for GPU, RAM and BOOT). If it lit up and stays on chance the mobo sensing something not right with the CPU. Try reinstalling your CPU.

 

2. Case Fans arent suppose to turn on without powering on the system. Check the 24pin PSU cable and maku sure you plug it properly.

 

3. Try resetting the bios/clear CMOS

 

4. Try updating to latest firmware.

 

I too upgraded from i5 3570k to Ryzen 3600 + b450 tomahawk MAX and i have experienced weird POST behaviours, such as wont boot to windows after shut down, no input signal detected, wont post etc etc. My workaround is to press the reset button imediately after i turn on the computer (press power on then press reset immediately) and everything goes normal.. so far.

[johnsoner13]

Thanks, I’ve tried these but to no avail and I ordered the same replacement parts. Does windows 10 have something to do with it? I was just trying to boot right into windows from my ssd with all my data already on it and after a bit of research read that i should have to completely reinstall windows for it to work.