New build problems!

I cant seem to get my 980ti to have get signal. Sometimes it will have a signal for only a few seconds and then lose it after boot. Using the motherboards onboard video I have no problem as long as the video card isnt in the pcie slots. MSI 980ti on a gigabyte z170 motherboard. Ive been trying to troubleshoot this for hours and Im compleltey lost at this point. Anyone have any suggestions? Need desperate help! thank you! this is a new build btw.