Problem turning on pc

[homework.is.amazing]

PC Specs:
I5 7600k
Z270 MSI M3 gaming Motherboard
ASUS 1060 3gb GPU
Corsair 500 PSU
2x4gb ballistix ddr4
1 tb hard drive
hyper evo CPU cooler

Ok, The problem that I am having with my pc is that when i turn it on with everything connected it turns on for a split second then turns back off and it repeats that pattern. When I unplig the 8 pin cpu power it turns on and stays on. I would like to know what i should do so once i connect everything together the pc wont turn on then off.Thanks in advance.

I just now found out that when i spply a little pressure onto the 8 pin cpu power the pc seems like it turns on but I still get no display.

 

[jay32267]

I would be checking my PSU voltages when the 8 pin is connected. It could be that something is dragging the voltage down on the PSU.