is my motherboars malfunctioning or is my cpu malfunctioning

[homework.is.amazing]

so i am having a problem with my motherboard or my cpu the problem is that if the power for the cpu is plugged in the pc will turn on and off and if the power for the cpu is disconnected it will turn on and a little red light next to something that says CPU turns on. now the thing i want to point out is when i turn the pc on when the cpu power is plugged in i noticed that the CPU light is still turned on. in the manual for the motherboard it says that if that light is on the cpu is not detected or fail. now the question is. is it the motherboard or is it the cpu that isnt working. also its not the psu since i tested it on a similar build and it worked.

PC SPECS:
I5 7600K
MSI Z270 Gaming M3
GTX 1060 3GB
Ballistix 2x4GB DDR4
Cooler Master 212 EVO
Corsair 500W 80+ BRONZE
1TB Hard Drive

If anyone could help me that would be great.

 

[why_wolf]

It's far more likely your motherboard is failing not the CPU itself. The only way to know for sure though is to either get another compatible motherboard or CPU and swap the parts to see what happens.