Grey screen on boot of custom build

[paultoffy]

 

Hello,

I have built a custom pc for myself and have have had some problems with it.
At first everything was running smoothly, I tried to install w10 from a usb and it worked for the first few steps, then my screen went black. After trying to figure out why, I found out that my gpu was not sending any signals, so I switched to my integrated graphics and it worked for a few days. Then, while trying to get my gpu to work, I deactivated integrated graphics and it probably switched to some basic graphics settings. Since then, I have had a green screen after the post and have not been able to see anything except for the bios and post. In the bios I saw that my mobo wouldn't recognise my gpu, so I tried another gpu. The mobo recognises the new gpu but I still get the grey screen. (Both my cables and my monitor work since I have used them with my ps4).

Any help is welcome

My build:
CPU i5-8600K
GPU Gigabyte 1060 OC Windforce
MOBO Msi Z370 PC Pro
CASE NZXT s340 Elite
COOLING NZXT Kraken x62
PSU Corsair 650W
GPU I used to try: Sapphire R9 290 Tri-X

[Fatelinha]

Are you certain the other GPU that you used is functional?

[userzero]

Sounds like the first GPU is dead and you need to do a power drain/cmos reset in order to get back in action.

[paultoffy]

21 hours ago, Fatelinha said:

Are you certain the other GPU that you used is functional?

Well yeah, both system (mine and my friends') i tried it on recognise it so yeah it works

 

[paultoffy]

21 hours ago, userzero said:

Sounds like the first GPU is dead and you need to do a power drain/cmos reset in order to get back in action.

In a few days I'm gonna get a new GPU but my problem rn is that I cannot install w10 because I get a grey screen even when I start the system from my usb