Question Blackscreen+no BIOS after installing new GPU

[Sternpaul]

Hello,
since my last question is still unanswered, I am trying my luck again.
I recently bought a new graphics card for my build, but my system is not detecting it. If I plug in my Monitor directly into the GTX 970, I get no signal. If I plug in my Monitor into the onboard graphics, I dont see the new GTX 970 in the device manager. I tried out everything I could find:

1. I deleted all the drivers for my old graphics card
2. I tried all the different outputs
3. I tried different monitors
4. I checked if the device manager lists the GPU as "hidden"
5. I checked with GPU Z
6. I checked the power connectors (1x6pin + 1x8pin)
7. I tried connecting my GPU with different cables from my PSU
8. I updated my BIOS to the latest version
9. I made sure I had "secure boot" off and "legacy" on
10. I checked if my PSU can handle the card
11. I pulled it out and plugged it back in several times
12. I even placed it in another system

Always the same problem: No signal. When I put my old graphics card back in, my system starts up like normal. I hope that somebody here can help my solve this problem.
My system specs are:
Motherboard: MS-7826
CPU: i7 4770 3,4GHz
GPU, old: GTX 760
GPU, new: MSI GTX 970 4G
PSU: 600W be quiet! System Power 9

 

[bniknafs9]

is your monitor brand new ? i had that issue it was elevated when i fiddled with the display port and hdmi version on my monitor .

 

[Sternpaul]

is your monitor brand new ? i had that issue it was elevated when i fiddled with the display port and hdmi version on my monitor .

Hey, thanks for the reply.
I tried it on multiple monitors, all of them work fine with other GPUs