All you can really do is check out the possibilities in the order of likelihood. Unfortunately, for the average PC user suspecting a fault specific to a board, the options are limited. Unless you have specialized test equipment and the knowledge to use it, you are basically restricted to the following:
* Check the connection- Do this by replugging the card into its socket.
* Replacement – if you are fortunate enough to have a functional graphics card handy, perhaps from an earlier upgrade, try installing this. If you don’t have another card, consider going out and buying the cheapest one you can find, as substitution is the only way to be really sure.
* Resource conflict – You could have a situation where by your graphics card is OK but is being prevented from working by another hardware device which is claiming the same system resources. The usual method of sorting out this type of problem is by using the Device Manager in the Control Panel. This however, requires access to Windows, which in this situation you obviously haven’t got. What you’ve got to do therefore, is one by one, physically remove every device in the system, restarting each time and seeing if the PC now boots. If and when it does, then the last device removed will be culprit. Once back in windows go into the Device Manager to resolve the issue.