8-pin CPU connector causes Computer to turn off right away

[Hrtguy]

Whenever I power on the computer it turns on for about a millisecond then proceeds to turn off right away. The normal lights flash and then immediately turn off. I noticed that if I unplug the 8 pin power connector for the CPU and leave the 24 pin alone it is able to turn on, just with no power to the CPU so I get the CPU error light. I tried playing around with it but couldent get much further. I tried checking the power supply and nothing seemed wrong. This only happened after I finished applying some thermal paste

 

[Dark Lord of Tech]

Specs please?

 

[Andy_K]

Sounds like there's almost zero contact with the heatsink to the cpu, or your power supply has had it 🙁

 

[Hrtguy]

IM actually not sure how to reply to answers so I'll just write them like this. ( If you could tell me that would be great)
4 GB Corsair DDR3 RAM
Intel i7 970
AMD RADEON R7 Graphics card
Intel stock cooler
LSP ULTRA 750w atx power supply
Asus sabertooth motherboard ( IM not sure about specific I just know the name)

 

[Dark Lord of Tech]

Is this a new psu or one you had been using.

 

[Hrtguy]

I've been using this PSU for the last year or so and it's worked fine with no problems whatsoever untill now.

 

[Dark Lord of Tech]

Is the PSU CPU cable seated properly into the PSU and board when this happens.

 

[Hrtguy]

Im quite sure it's in the PSU properly as it dosent seem loose and it's in the motherboard properly. I've also tried the 4 pin CPU connector and also got the same issue.

 

[Hrtguy]

I've tried running the motherboard out of case with just CPU, fan, ram, and PSU and still got the same error with the 8 pin.

 

[Dark Lord of Tech]

Bad CPU power port ON THE BOARD or Defective 8 pin on PSU.

 

[Hrtguy]

Is there anyway to see if it's defective?

 

[Dark Lord of Tech]

Do you have another PSU you could try with?

 

[Hrtguy]

Do you have another PSU you could try with?

No i do not. Ive been reading up on the issue and most people in the end had a problem with their motherboard so that may be my issue too. I'm mostly just confused how this even happened in the first place since all I was doing was changing thermal paste.

 

[Dark Lord of Tech]

Hard to say , I would say most likely the board , it is in most cases.