Installed a video card but computer keeps rebooting

[ibeecrackin]

I took my old Sapphire HD 7870 and installed it into my new computer. Everything turns on including the fans on the video card, but it turns off after 3 seconds and reboots itself. I use the onboard vga for display and it works fine. Is the videocard broken? it worked on my old computer just fine.

Gigabyte z97-HD3 motherboard
i5 4670k cpu
16gb G.Skill RipJaw Ddr3 Ram
700w Coolermaster Silent Pro PSU

 

[herrwizo]

Did you, by any chance, forget to plug the 6 pin power connector? Just asking...

 

[ibeecrackin]

Did you, by any chance, forget to plug the 6 pin power connector? Just asking...

It is plugged in all the way

 

[herrwizo]

Before proceesing, just make sure it definitely works in your old computer and that nothing burnednit during the transfer, such as static electricity. Also, you can try using the other pcie slot.