Help! My power supply is not working!

[C4nary]

I recently bought a GTX 750 ti SC and a Antec 550-watt power supply. I decided to install both of them, because my previous GPU was a Radeon HD 5450 and I had a 400-watt PSU. The video card was easy to install, but it took me an hour to get the PSU out. When I put the new PSU in, and turned on my PC, the LED came on but the heatsink fan wasn't spinning, my case fans didn't spin, and my PC didn't work. I tried putting back the old PSU, no luck. I tried putting in the Radeon. No luck. Help!

 

[ctsvette]

Make sure you're not forgetting the 4 (or 8) pin auxiliary power connector by the CPU.

 

[C4nary]

I tried that, and my fans spun for half a second, then stopped. My LED stayed on during the entire process.

 

[Cristi72]

Hello,

Are you have a brand system, such HP, DELL, etc? If so, be sure the new PSU is compatible with the motherboard.

 

[C4nary]

Actually, it's working now. Thanks for the answers!