I took my iMac in to Apple Store about 9 days ago to fixed because of an unusual amount of kernel panics I was receiving on the daily. You can read more about this in detail within this thread: http://forums.macrumors.com/showthread.php?t=1402907 I was very specific with the "tech" before turning in my iMac. I told him that I pulled out all 16GB (4X4GB) Corsair RAM and replaced it with the Apple stock RAM and was still was receiving kernel panics. I also explained to him that the kernel panics would happen in safe mode, thus, ruling out any third party kernel drivers causing the issues. I gave him about 10 different error codes I was receiving from the Apple hardware test and made sure he included them in his description of the problem. I also made him note that some of the MOT errors were errors that people on Apple's support forums described as likely problems with the logic board's fan controllers properly spinning fast enough to keep components cool. He immediately dismissed this and said heat has nothing to do with it. Well 9 days later I get my iMac back and bring it home only to find more issues than I started with. First of all, they took one of my 4GB sticks out and taped it to the foot of the iMac, which I'm guessing they figured was bad and the cause of the problem, but in reality they're wrong. I've already swapped the sticks around multiple times and still got the same errors, which I explained to them when I dropped my iMac off and now I am still getting the same errors even after the "repair". Secondly, when booting, my screen flickers intermittently enough to become an annoyance. Thirdly, with no keyboards plugged in, the iMac will just begin writing letters and numbers extremely fast and at random. Lastly, I am receiving really loud beeps like the ones you get when your pressing a key on the keyboard that has no function. In closing, I looked at my receipt when I got home and it says that the work that was done was software repair! Are you kidding me? Or do they just think I'm stupid! What did they do? Run Disk Warrior and repair permissions? What a sorry excuse for saying they did a repair when they most certainly did next to nothing. I am sorry if this sounds like a rant, I'm just extremely frustrated as I need to finish a wedding video very soon. If anyone has ANY ADVICE or INPUT, please feel free to chime in!