Thanks for your reply.
The card is fairly "new". It was replaced by RMA back in July. It's been working great up until the whole PSU incident. But I'll take another look at it and see if there's any dust I may have overlooked.
Going to apply some Arctic 5 on the GPU. Just a small dot of thermal paste in the center then re-attached the GPU heatsink, right?
Also, How long should it take for the paste to expand and cool?