Black Screen seconds after startup, computer still running

I've been running my computer for years without problems. I recently bought a new graphics card and about a month after that the screen displays 'No Signal' About a second after displaying the HP logo. It still happens when trying to access the BIOS menu. As a solution to this I've tried replacing GPU, PSU, screen, hard drive and RAM but the error persists. I've also tried resetting the CMOS battery. Does anyone have a clue on how I can fix this? Do I need to buy a new CPU or motherboard?

It may be a GPU driver problem. Uninstall the graphics driver using the manufacturer's instructions to remove all previous drivers and try using the latest WHQL driver for your GPU. I would also use Autoruns to check for remnants of previous drivers - e.g. if you previously had a NVidia GPU and have moved to an AMD GPU (or vice versa) you may find left over remnants of the previous driver.

Steve C said:

It may be a GPU driver problem. Uninstall the graphics driver using the manufacturer's instructions to remove all previous drivers and try using the latest WHQL driver for your GPU. I would also use Autoruns to check for remnants of previous drivers - e.g. if you previously had a NVidia GPU and have moved to an AMD GPU (or vice versa) you may find left over remnants of the previous driver.

How do you mean I would do this without access to a screen?

Can you boot into safe mode and install drivers from safe mode?

Unfortunately not, the screen turns black even if I enter the BIOS menu.

Maybe it's time to contact your motherboard manufacturer to find out how to enter the BIOS and reset the defaults. Does your motherboard have a built in Intel GPU? If so, you could remove/disable your add-on GPU and see if you an boot from the Intel GPU.

It doesn't have a built-in one. I'll contact HP and see if they can help.