I have replace motherboard on an Acer Aspire m3641, The problem i was getting was that when i put a load on the video card it would freeze, (watching blu-ray, or other full screen movies, or even a game). I had speenfan up and runing at same time so when it froze I could see the stats, nothing seemed to be out of the ordinary. I have no problem loading up computer after freeze. I cant seem to see whats causing this issue. It happened with original motherboard and with the new 1. any help would be much welcomed.
The issue can be caused by your ram, Overheating CPU or overheating gpu.
Reset the bios settings first and make sure that all the temperatures are normal at load. If there is abnormal temperature, replace thermal paste and/or check that the heats ink is in good contact with the CPU and the gpu.
Have only one ram installed at once and then try.