Hi. Every so often the screen on the iMac late 2009, which has the 4850 GPU (Mobility) would become garbled/distorted but only by playing a first person shooter would it go back to normal (and changing the display or color profile from iMac back to sRGB to bring back the garbled icons below to normal).
When the screen becomes garbled/distorted the system does not crash or freeze by the way. The temperature when it's on load is 78 Celsius (GPU Diode) and 76 Celsius (GPU Heatsink). Screenshot:
Is this a software problem or a hardware problem. I've experienced GPUs that are damaged or have overheated but when you use it the whole system would freeze or would not boot at all but this one, as mentioned, it does not crash and it's strange that it goes back to normal when you play an first person shooter which should be making things worse because it stresses the GPU. What could the problem be and what could be the fix?
Thank you in advance.
God bless, Rev. 21:4, Eschatology