Answer to "After HDD Replacement, Won't turn on"I’m having the same issue, here’s my scenario: Bought a used late 2009 iMac in mint condition. Reinstalled OS, etc., its been working great. Decided to upgrade RAM and hard drive to ssd. I have experience replacing drives, broken ipod/ipad screens, etc.. I followed the iFixit guide (also reading through all the comments) as well as watched the OWC video. While I had the iMac open I cleaned out dust with compressed air and vacuum. Before people freak out, the vacuum did not touch any components. I hold the nozzle of the vacuum near where I blow the compressed air in short bursts so it sucks up the airborne dust. I have used this approach many times with zero issues. Went to install new SSD and realized I had wrong adapter ( was using one I had on hand). Reinstalled original drive but now no power when I turn it on. No fans, no nothing. Tried resetting SMC but nothing. Thought maybe I had blown the power supply so took that out to inspect but looks fine (not that I would’ve been able to see anything, but was...