Dimension E520, slot 1 PCI failure

Hi,

I have a Dell Dimension E520 desk top which I have added extra RAM (to 4GB)and Hard drives. It has a AMD Athlon 64X2 2.3 GHz processor. I am running Windows 10 Home version 1809 as the OS.

I had also fitted a ATI Radeon Sapphire HD2450graphics card with 1.0GB of DDR3 RAM. My monitor is a Dell 1907FP analogue and digital display.

All has worked well for quite a few years until recently on start up the screen didn't come on. I tried a number of things finally attaching the analogue cable to the on board graphics card, this at least resulted in the screen being on and being able to use the computer. I decided to purchase another graphics card (hoping that this was the problem) and purchased a near identical one (except this one has 2.0GB of DDR3 ram). This didn't work and when I looked in the BIOS the card attached to the  PCI slot one was not recognised and it stated unattached (or something similar).

It seems to me that PCI slot 1 is not working. Can I have inadvertently done something to either the BIOS or within the workings of windows 10 to cause this?

Please help

Colin