So, now and then I buy some computers odd behaving or completely nonfunctional computers in hope to fix them. I came across this one iMac which the seller says is 21,5" model from 2010. He says that the machine works well except for random times when the video hangs but all sound continue to function, after some time everything works again. There are no artifacts or anything unusual on the screen during that time. So, my question is if anyone can confirm that these are common syptoms with GPU failure or beginning of failure? Common with this model? Based on Googling it has Radeon card so it could very well be it, powerful card in tight enclosure = not good for reliability. EDIT: No sorry, it has Nvidia GeForce 9400M card !