Built new PC need help with gfx card!

[samgwhitney]

So this is my second pc I have built so I am not that new to building world. Anyway, the main problem I am having is with the gfx card (Radeon HD 7770). When I power up the computer the fan on the gfx card spins for ruffly 1 second then stops, and displays no picture. When I put the gfx card into my moms old Dell it runs and fine and it works and displays a picture. When i put her old gfx card (Nvidia 8600gt) the fan spins but I still receive no picture. Im not sure if its not getting enough power or I have the wrong parts or what. My computer parts are:

PSU XFX PRO550W
MEM 2Gx2|GSKILL F3-12800CL9D-4GBRL
HDD 1T|ST ST1000DL002 5.9K SATA3G
CPU AMD|PH II X4 965 3.4G AM3 R
DVD BRN ASUS | DRW-24B1ST/BLK/B/AS
MB MSI 970A-G46 AM3+ AMD 970 SATA 6Gb/s USB 3.0 ATX
VGA HIS|H777F1G2M HD7770 1G R
CASE FAN|XIGMATEK XLF-F1253 R

If I could get any help it would be greatly appreciated.

 

[completelyrandomname]

I am no expert in problem diagnosing, but could be a faulty PSU, mobo PCI slot, or just the cable itself. What cable are you using? DVI? VGA? HDMI? Try replacing the cable first.

 

[samgwhitney]

I used a VGA then DVI for the HD 7770 and still didnt work, but for the 8600gt I tried everything on mine and it doesnt work but on my moms it does. Trying a new PCI right now as we speak.

 

[samgwhitney]

Just tried different PCI slot but that didnt solve anything, still no spin on the fan, thinking its the power supply, not enough power.

 

[drinkingcola86]

Looking at the picture of your MB. it has a 8 pin cpu power up near the socket? did you plug it with the 8 pin from your power supply? The reason why I ask this is because it sounds like the lower end of you MB isn't getting the power it needs to run everything.

 

[samgwhitney]

The 8 pin is plugged in, tried my 7700 still didnt work, tried the 8600 and fan still going but no picture.. I dont know what im missing or... If i just need more power, but my moms computer is only a 350W and its running everything just fine.

 

[drinkingcola86]

My guess would be either you power supply is bad or your MB is bad on the lower end. which can happen.