I understand that you updated the BIOS and now your video card wont work with your motherboard.
In regards to your inquire, it is possible to roll back the BIOS by doing the same procedure that you used to update the BIOS but with a previous version. At this time if you are not able to get any display with another video card, I recommend you to perform a BIOS recovery using an older BIOS version. You can find the instructions at the following web site:
Please rollback one version at the time until your video card starts to work. If you are not receiving any isplay, I recommend you to allow the system to run for at least 7 minutes while doing the BIOS recovery before you turn it off to prevent BIOS corruption.