I was trying to upgrade my son's GTX-750ti with my old EVGA GTX-680 SuperClocked card, but it made the system so unbootable that I couldn't even open the BIOS CMOS settings utility. The system would randomly hang at the BIOS splash screen, list of attached drives, and randomly reboot - without ever trying to boot the OS (Win10-64). Eventually I just had to give up, and go back to the original GTX-750ti video card - which got it working instantly, but I have no idea why...
The system is built on a Gigabyte AMD A3+ motherboard (GA-78LNT-S3 at it's latest 2014 BIOS update) running a 3.8GHZ FX-4300 4-core processor, with 8GB DDR3 memory. Yeah, I know it's a moderately old motherboard, with only 1 16xPCIe slot - but I couldn't think of any reason it shouldn't be able to use the GTX-680 successfully... The latest and greatest GeForce drivers were already on, but that's probably not relevant since it never got close to actually attempting to boot the OS. We tried powering the system off and restarting the boot attempt multiple times, and could see that all the expected HDD's and SATA devices were recognized by the device listing that would sometimes appear before the system totally hung. Even from the CMOS splash screen, none of the key sequences were recognized or acted upon to enter the CMOS set up, or other BIOS utilities.
I was trying to remember if my EVGA GTX-680 needed a BIOS extension or anything to work, and if I had to do anything weird to the BIOS to install that - but could not find any reference to anything other than the latest GeForce drivers on the EVGA product support page...
So does anyone have any idea why this GTX-680 fails to work with the Gigabyte mother board I was trying to use it in? I really wasn't expecting any problem when I put it in, but was surprised how it made the system totally unbootable.
Thanks for any thoughts, explanations, or suggestions anyone may have!