Thanks again for all the suggestions.?
I took out the ATI Radeon HD4870 and took it apart for the first time in 11 years. While I clean out the Mac itself, I have never taken the GPU apart - never thought it would need that.
Man, was it plugged up. The heat sink had no openings left for air. Cleaned it out and all is fine again. So the recommendation to clean it was right on - I just never took it to mean take the GPU apart.
Thank you.
Ihor
