Question Pc not not working with graphics card installed

[Mistborn_123]

Current Hardware:

Cpu: intel i7 3370k
Gpu: geforce gtx 1070
Motherboard: gigabyte z77x-ud3h
Psu: corsair gs600
Ram: corsair (4×4gb)

Originally I had a gtx 660ti in my set up, when I was gaming my moniter lost signal and my keyboard stopped working, I was forced to hold the power button to turn the PC off.

When I turned my PC on again the case, cpu and gpu fans ran like crazy (the case lights lit up as normal) but nothing appeared on the monitor and I had to hold the power button to turn my PC off again.

I found out that once I removed the graphics card my PC ran as normal. Wanting to replace my gpu I bought a gtx 1070 and installed it, but when I turned it on it was stuck on the motherboard page.

After some research I rebooted the CMOS and updated the bios, but now when I turn my PC, there's no signal to the monitor (the case lights and fans work as intended). My PC still works fine without the graphics card though.

I did try different monitors and cables but I still get the same issue with the gpu

I'm stumped and have no idea what to do.

 

[PC Tailor]

Did you clear all previous drivers using DDU in safe mode?
Do you have latest BIOS installed?
Are you sure the new GPU has been connected to the PSU properly? (Obvious, but covering all grounds).

You lost signal with the GTX 660Ti originally, and now get no signal with the 1070? If so - follow all of these steps: No POST / Video / Boot Guide
Are you able to test the GPU im another rig?