GTX 1080 TI only working in BIOS

[JCGJCGJCG]

Hi, I am trying to install a Geforce GTX 1080 TI on my Asus Rampage II Extreme Motherboard (I know, it is a bit older, but this shouldn't matter that much, right?) I have a 650 Watt PSU and the card is connected via 2 6+2 plugs. When I boot, the PC starts and I can enter the Bios setup. But i won't get past the Bios posts, the monitor switches off afterwards and shows no signal. Could this be a power issue, despite the 650 W PSU? My old graphics card works fine as soon as I switch (a Geforce GTX 670). System is latest Windows 10 and I uninstalled the old graphics driver before.
Thanks!

 

[marksavio]

you only said "..card is connected via 2 plugs". i hope you meant from 2 different PCIE power cables.

 

[ShadyHamster]

Sounds like the system is switching to integrated graphics after it passes the bios, try manually disabling the igpu in the bios, even though this should happen automatically.

Silly question i know but i have to ask, are plugging the monitor cable into the 1080 ti?

 

[JCGJCGJCG]

you only said "..card is connected via 2 plugs". i hope you meant from 2 different PCIE power cables.

Yes, plugged in via two 6+2 PCIE plugs

 

[JCGJCGJCG]

I actually have no on board graphics it could switch to, so that might be true. But i had connected both display port and HDMI cables. And I can see the Bios, so the cables are definitely connected...

 

[JCGJCGJCG]

Solved, the Motherboard has only PCIE 2.0 and needs 3.0. So I am building a new one now🙂
Thanks!