I am both fascinated and disheartened by these stories. I'd like to add my own and if anyone has any suggestions about how to proceed, I'd sincerely appreciate it.
I have mid 2010 iMac 4GB 3.06 GHz core, 21.5 inch, same as ThEagleye.
I took out the 4GB and replaced it with 16GB almost immediately. Not even a year into owning the unit, (2011) I had problems. It ran slow, crashing, etc. I took it in and the hard drive was replaced (Apple care) It ran "fine" until summer this year (2013) when I began to get the "spinning wheel of death" regularly. I could do nothing except hard reboot, no "Force Quit" would work. Once I rebooted it would work again, but for increasingly shorter periods of time. When I turned it off at night, that seemed to help it work for longer periods of time. Still, I couldn't get through an entire day.
I took it in again and they replaced the hard drive again. I really began to feel frustrated because I felt like they replaced the hard drive because they couldn't think of anything else to do. Not two months later, I get the same spinning wheel of death again. Same e act experiences. I took it in again, and explained that I didn't think it was the hard drive, but explained that I had a feeling it was over heating as it was getting VERY hot. They told me that was totally normal and ran a short diagnostic test. Explaining that the RAM was probably the problem (I always feel that they start explaining what ISN'T their responsibility first and scape goat it immediately) but that they would look at it and try to replicate the problem. Less than a day later they called back & said was definitely the 3rd party RAM. I started to feel like these guys were just guessing. So I brought back the original RAM for the test.
Lo and behold. it's not the RAM. Now, they think it "might be" the logic board. Which will take 3-7 business days to get.
That's where I'm at now. From reading here, I think it is over heating and fried the logic board.
I'm assuming they will replace the logic board and hand it back to me "good as new" until this happens again (and Apple Care expires this December) Any suggestions on how to proceed from here (besides buy a PC)? I need this machine to last another year at least and this is obviously a faulty hardware issue.
Thanks in advance for any suggestions.