What is happening :(

[ech0afterme]

Hello there,

 

So there's my computer with a CPU without integrated graphics.
So last week, my display just gave out (booting without a display unfortunately), and first thought is that my GPU spoil.
Hence, I replaced my GPU and got a second hand (tested working new) today, but despite plugging in the new GPU, my display is still not showing :c

HDMI cable and monitor is confirmed to be working.
What should I do now?

[AndrewZScorpion]

Try the card in a different PCIe slot if you can.

[WaggishOhio383]

3 minutes ago, ech0afterme said:

Hello there,

 

So there's my computer with a CPU without integrated graphics.
So last week, my display just gave out (booting without a display unfortunately), and first thought is that my GPU spoil.
Hence, I replaced my GPU and got a second hand (tested working new) today, but despite plugging in the new GPU, my display is still not showing :c

HDMI cable and monitor is confirmed to be working.
What should I do now?

Have you tested the display with another device to be sure that it is still working? If your graphics card was broken, the computer likely wouldn't boot at all, but from what you're saying it seems like the computer is booting fine (just without video out)? This likely means either your monitor is broken, or something is wrong with your motherboard. Try clearing the motherboard CMOS either by using the CMOS clear jumper, or by just taking out the CMOS battery for 30 minutes or so (with the PSU unplugged, and making sure to hold down the case power button for 30 seconds while it's out to drain all power from the system).

 

Another thing you could try is running the GPU in a different PCIe slot if your board has one, as @AndrewZScorpion already mentioned.

[ech0afterme]

Monitor is working fine. My motherboard was recently replaced, could it spoil that fast? 

Also my motherboard only has one pcie slot

[ech0afterme]

EDIT: Update

So I basically dismantled everything, reseated my GPU, ram etc. and also reseted my CMOS by using the CMOS Jumper on the motherboard.
I then turned on and to my surprise I saw output saying that my BIOS was reseted.
All was well and Windows booted to my usual desktop.
However, I was trying to plug my mouse/keyboard in and fiddle some wires on the back at the IO of my motherboard when the screen goes green, and then blacks out again. I replugged my HDMI cable, and tried to reboot my PC and now the monitor says no signal again.
What could be the problem here exactly?