CPU is in the OP, as for cooling solution I'm not entirely sure what you mean by that. Are you refering to the thermal paste or the heatsink?
Yes, I see you added the CPU to your OP, thanks.
As for the cooling solution, I was referring to the heat-sink.
At this point it could be moot though.
It's unlikely that you have two bad GPU's, but if you still have the old one you could try it and test.
However, your description of what led up to this leads me to suspect the CPU and/or the motherboard is damaged. (leaning toward the CPU at this point)