Recently I wanted to install a Gigabyte Radeon HD7870 in an older PC with an ASRock P67 Pro3 Mainboard. The surprise was big when the monitor didn’t show an image and the computer didn’t boot. Instead, the mainboard’s debug panel showed the error code 97. According to the manual this means “Console Output devices connect”. Not connectED but more likely in the process of initializing the graphics card and failing while doing that.
There’s an easy fix for that. Installing the latest BIOS version (3.30, installed at the time was 2.02) resolved the issue and the computer booted without problems.