You just finished installing a new video card into your computer, and after turning everything on you get a black screen. There is no native support for your video card because it's not listed in the supported list or it's not even known to operate in the PCI slot that you have installed it into. So naturally when you turn your computer on you would think everything is working fine, except for the fact that the screen stays black. What might be the cause of it?


Insufficient Power?


One thing that comes to mind is an insufficient power supply. Your computer's motherboard requires a certain amount of power from the wall outlet or an external power source such as an electric battery pack or a generator. That power needs to be distributed from the outside power source through some type of internal circuitry that connects to your motherboard and then supplies power to your computer's power supply.


If there is a problem with that internal circuitry, or the new video card you installed requires more power from it than what that circuitry can support then you would end up with a black screen as soon as you turn on the computer because the power wouldn't be able to reach your motherboard and/or CPU.


Inadequate Cooling?


Another possibility could be inadequate cooling for your brand new video card. If there was not enough airflow through the computer case when you installed your new video card, or if there wasn't enough room around it for any air to flow between the back of the video card cooler exhaust vents and anything else in the case (such as an additional hard drive or an open PCI slot) then the video card could overheat and cause problems with its functionality or even cause damage to it.

 

Insufficient Power Supplies

 

Sometimes you might discover that after installing a new video card into your computer, turning it on, and checking for native support in your computer's BIOS you still get a black screen when you turn it back on because your motherboard only supports up to version 1.4 of PCIx. The PCIx revision number can be found printed somewhere on the bottom side of your motherboard, or by looking at the documentation that came with one of its drivers. This is quite common among many motherboards today, especially cheaper ones where they don't even list their PCIx revision in their manuals. If this is the case then you would need a power supply with an external power connector that supports PCIx 2.0 to be able to provide enough power for your video card.

Otherwise, it wouldn't even turn on unless you connected a Molex connector from the outside power supply unit directly into the back of the video card which might cause problems depending on what type it is where if that's done then you would have just wasted your money on installing a new video card because as soon as you turned off the computer it wouldn't work unless plugged directly into a wall outlet with a direct line-of-sight connection.


Wrong Connector Type?

 

Another possibility is that your new video card only requires a 6-pin connector for power, but the outside power supply unit you have doesn't have one connected to it. If that's the case then you would need to buy an adapter that converts a Molex connector into a 6-pin connector to plug your video card's power cable into it. Otherwise, without connecting one of those adapters your old video card wouldn't work either because it also required the same type of external power source as mentioned above.


Damaged Motherboard?

 

Another possibility is that the motherboard is damaged, or that it's just too old and doesn't support PCIx 2.0 or whatever newer version came out after it so there isn't any native support for what you installed. If the BIOS doesn't list your new video card in its hardware compatibility list of supported devices then you would get a black screen when you turn on the computer because it wouldn't be able to communicate with your new video card at all.


Input Delay?


Finally, another possible reason could be some type of input delay in Windows. That means that while your monitor is plugged into the back of the graphics card through an HDMI cable, for example, Windows still thinks that it's plugged into your motherboard instead. This means that while you could see the POST messages and all of your BIOS settings when you turn on your computer, once Windows starts loading it would display a black screen until you plug your monitor into the back of your graphics card instead because it will only use the video driver for whatever GPU is plugged into it at boot time. This can be fixed immediately by going to "Change Adapter Settings" in Windows and then right-clicking on the one that's connected to your motherboard and choosing "Disable". Once disabled, go ahead and restart your computer which should load up Windows with no problem. On the other hand, if there isn't any input delay or this doesn't resolve your issue then I would recommend contacting whoever sold you the video card and asking them for an exchange. If neither of these options works then there might be something more seriously wrong with your computer which would have to be addressed by a professional technician, but I think this will at least get you started in the right direction.


Conclusion


This is probably one of the most common issues that people run into when they are trying to hook up their shiny new video card to their current computer. If you happen to have just enough money for a cheap no-name brand video card then chances are it won't even work unless you buy an expensive power supply unit too, but if you're lucky and bought a quality unit then chances are it will actually come with its power supply cord and all you'll need is some type of external power supply unit with the proper wattage rating for your video card instead.