If you have not changed yours yet - just make a copy first
 
Contact customer service, they should be able to help you out.
 
Have your model number & serial number handy
 
(edit typo)

To save your current/original video BIOS, use GPU-Z and click the 'Save BIOS' icon, or use the --save command in NVFlash.
 
You can find original video BIOS collections here, or you can contact EVGA support to get one.
 
If you use GPU-Z, it may need to stop the Graphics Driver to save the BIOS and will popup a confirmation box..If you click the 'Save BIOS' icon and your screen flashes, changes to solid color, or otherwise becomes unreadable, don't panic, just press the keyboard Enter key because the confirmation box popup defaults to 'Yes' and pressing Enter will select 'Yes'..After you save it, the Graphics Driver will be restarted and returned to normal.