Hmmm, I wonder if there are similar tricks for newer hard drives. I have a 2010 iMac that has a seized or "otherwise non-booting" hard drive, just randomly wouldn't boot one day. I can only guess there is a mechanical problem like this, because those aluminum iMacs were notorious for running too hot internally and basically overheating the HDD. Same problem on my wife's 2008 iMac, that machine burned through 3+ HDDs due to the heat issue.