Question Problems with new 1070

[Eskil-123]

So i just got a new 1070 today, but there seems to be something very wrong going on.
Whenever i go start up my PC, it wont boot.
However if i use a second card in another pcie slot, it will boot up just fine, without even plugging the second card to a monitor.
It is also very clear that the 1070 is working properly, fans spinning under load so on.
The only thing i that i cant boot without another graphics card, and i don't have on-board graphics either.

Thanks a lot in advance

 

[PC Tailor]

What is your full system spec - including PSU make and model.
Have you also tried the 1070 in the other slot by itself?