I installed a new power supply but the computer won't boot

[douhua1999]

So I recently got this new power supply (corsair CX750M) for my pc (upgrading from an older OCZ psu). When I installed the new corsair psu and tried the power button, the cpu and psu fan would spin for a second, then stop, and the computer wouldn't post.
The funny thing is that when I reinstalled my old OCZ psu, my pc boots and works just fine.
I tried the paper clip test on the new corsair psu and it ran for as long as it was powered (indicated by the psu fan).
I don't think the motherboard is being powered because there is this little red light on my motherboard that lights up when a psu is plugged in (it lights up with the old psu, not the new one).
Thanks for taking the time to read this, have a great day!

Update: The red light is now on indicating the motherboard is powered, and things plugged in through USB to the computer is also powered, but still only the cpu fan and psu fan spin for a second before everything turns off again.

My pc specs are:
Asus Z87 Pro
EVGA Geforce GTX 660 SC
Intel i5 4670k @3.4GHz
HyperX Fury Red Series 8GB (2 x 4GB)
Western Digital Caviar Blue 1TB
Samsung 750 Evo 250GB

 

[Simthaniel]

Are you sure that you plugged everything in correctly with the new psu

 

[douhua1999]

Are you sure that you plugged everything in correctly with the new psu

Yeah, I plugged everything in exactly as I did with my old psu.

 

[turkey3_scratch]

May sound stupid but is the power switch in the correct position on the back of the PSU?

Edit: Well, yeah, since paperclip worked I suppose it is.

 

[douhua1999]

May sound stupid but is the power switch in the correct position on the back of the PSU?

Yeah, it is switched on. It is for sure because the cpu fan spins for a second or so.

 

[JamesSneed]

Since you do get some power for a second then the PSU is trying to fire up. I would check the 24 pin connector is seating all the way(sometimes they take a bit of force when on new PSU's). Also make 100% sure you hooked up the 4 or 8 pin CPU power cable properly and didn't do something by accident like for a PCI connector into the CPU power slot. Those tend to be the two things people make mistakes on if they don't build PC's to often.

 

[douhua1999]

Since you do get some power for a second then the PSU is trying to fire up. I would check the 24 pin connector is seating all the way(sometimes they take a bit of force when on new PSU's). Also make 100% sure you hooked up the 4 or 8 pin CPU power cable properly and didn't do something by accident like for a PCI connector into the CPU power slot. Those tend to be the two things people make mistakes on if they don't build PC's to often.

I definitely used the proper cable for the CPU (because the cpu powercable has CPU written on it),
but I will make sure that the 24 pin connector is in all the way when I get home.

 

[turkey3_scratch]

Plug something into the USB port, it should work when the PC is even off. Does it work?

 

[douhua1999]

Since you do get some power for a second then the PSU is trying to fire up. I would check the 24 pin connector is seating all the way(sometimes they take a bit of force when on new PSU's). Also make 100% sure you hooked up the 4 or 8 pin CPU power cable properly and didn't do something by accident like for a PCI connector into the CPU power slot. Those tend to be the two things people make mistakes on if they don't build PC's to often.

I made sure the 24pin was secure. This time the red light indicating the motherboard was powered turned on. The computer still didn't boot, it did the same as before.

 

[douhua1999]

Plug something into the USB port, it should work when the PC is even off. Does it work?

Yeah I just tried plugging my phone into a USB on the computer and it charges, so the motherboard for sure is powered. I'm starting to think then it must be the CPU power?

 

[douhua1999]

Ok so I finally got the pc to work. Thanks to JamesSneed I got the motherboard to be powered (stupid of me not to think of this before hand). The pc still didn't boot, only because I was using the ocz cables to power my ssd, harddrive, etc. (I was still using the ocz cables because they were already in my pc after I reinstalled the old PSU). Once I switched those out to the corsair cables, the computer worked fine. I wasn't aware that basic power cables for storage drives would be affect the computer.

Thanks again for all the help everyone.

 

[turkey3_scratch]

Yep those cables are not electrically compatible. Glad it is solved! Enjoy your new PSU.

 

[douhua1999]

Yep those cables are not electrically compatible. Glad it is solved! Enjoy your new PSU.

Yeah thanks for taking time out of your day to help!