|You know, static. You walk across a carpet on a dry day and touch something metal and get a shock. Touching the metal discharges the static buildup in you. The metal is a ground or partial ground. An ideal ground would be something like a metal faucet handle. Touching the metal is referred to as 'grounding' yourself. That way when you touch electronics the static doesn't ground though the circuitry and possibly ruin things.|
A grounded outlet is one with three prongs, the bottom rounder one being the ground. Sometimes idiots cut off the ground prong to use in an ungrounded outlet or with an extension cord that has no ground prong.
A bad ground may have nothing to do with the power cord. It could be a internal fault in the device.
I'm not saying your problem is a bad ground--just that it could be.
I know of no practical way to test a graphics card except to plug it into a working computer.
Oh, should have asked earlier, does your graphics card need a power connection from the PSU? If so, is it connected?