I've been having problems with getting my ASUS M5A78L V2 motherboard to recognise the AMD HD7850 2GB DDR5 graphics card (manufactured by Sapphire) for about a year now. Everytime the card is connected, there's nothing on the display beyond the windows screen. On the other hand, the system is working well with no graphics card involved. I've tried enlisting the help of a computer professional who tried to use other cards but to no avail. We've also tried using VGA to HDMI and VGA to DVI converters but they have not worked. I've been using an 8GB ram supported by a AMD FX6300 processor.
The PC was assembled in 2014 and worked fine till last year when the power source melted. A new power source was used which is when the problems arose. Could the problem be because of the new power source or because of the motherboard since no cards are working? The computer professional says it could be the latter but I'm not entirely sure.
Help is greatly appreciated since as you would've guessed from the above paragraphs, I'm not an expert myself.