PC stops working when I plug in CPU 4+4pin cable

[neevee]

I recently built my new PC. When I first tried to start it, nothing happened. I then removed all the power cords except the 20+4pin motherboard cable. when I turned on the computer the CPU and GPU fan started up. When I tried again with the CPU cord plugged in, it stopped working again. The fan on the PSU wasn't going at all during any of this.

Should a get a new PSU and return the one I have?
are there tests or things I could try?
Any help is appreciated

my spec are:
Asus M5A97 R2.0 ATX AM3+ Motherboard
AMD FX-6300 3.5GHz 6-Core Processor
G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1600 Memory
Gigabyte G​TX 950 2GB​ OC Graphi​cs Card
SilverStone SFX-L 500W (But it says it compatible with ATX as well via a bracket)

 

[Xibyth]

It may not be an issue with compatibility, it is also possible the power supplies just doesn't have enough oomph for a full at board. Does it work with just on of the two sides plugged in.

 

[Rogue Leader]

Thats a decent quality PSU, the fact its not powering on when thats plugged in tells me there is a short somewhere, either in the PSU, or on your motherboard. Make sure all your standoffs are screwed in and there isn't an errant one touching somewhere on the board.

 

[InvalidError]

When I tried again with the CPU cord plugged in, it stopped working again. The fan on the PSU wasn't going at all during any of this.

If you turned it on but did not get any signs of booting, that does not count as working: all that tells you is that fans are receiving power of some sort but the system is still dead. The computer cannot boot without the 4/8-pins CPU power connector.

If the PSU keeps shutting down when everything is CORRECTLY connected (I have lost count of the number of threads on the forum where people start "PC not booting" threads and it turns out they forgot to plug something in), it means you either have a dying/dead PSU, a dying/dead motherboard or something else shorting the PSU out, such as an extraneous motherboard tray stud.

 

[neevee]

It may not be an issue with compatibility, it is also possible the power supplies just doesn't have enough oomph for a full at board. Does it work with just on of the two sides plugged in.

I actually went to the local computer store and they gave me a few spare ones to try (CPU cables) turns out the cable that came with the PSU was short circuiting the system.

Thanks for the reply.