Computer Won't Start: Gpu fans turn on then off (please help)

[EliZGaming]

My computer ran perfectly fine with my old setup.
i5 2500k
geforce gtx 750ti
500w
Hyper x ram
Windows 8
Then once i got my new gpu ( Sapphire nitro r9 380 4gb) 2 things happen.
1. My monitors get no signal and stay black
2. The Gpu fan just spins for like 5 seconds and turns off and does that repeatedly.
I'm quite new to computers but any help is very much appreciated

 

[kmr1154]

If i am correct... Your new graphics card requires 33 Amps. Your 500W psu is probably weak to power this card, that's why you can't run it. You need at least 600W psu from a good brand like seasonic or corsair or 750 watts if it's generic brand... This card requires 6+2 pin pci power...