Without that special Thermal Sensor Cable, apparently your iMac will spin the Hard Drive cooling fans up and make a lot of noise. If you have some of these parts or tools laying around, then you could get away with purchasing this kit instead: OWC In-line Digital Thermal Sensor for Hard Drive Upgrade for 27″ iMacs 2012 and Later To make my life easier I order the OWC Complete Hard Drive Upgrade Kit Including Tools for all 27″ iMacs 2012 & Later for about $53. Last update on / Affiliate links / Images from Amazon Product Advertising API There are several detailed YouTube videos that show you how to do this I used the following one from OWC and watched it a few times to get familiar with the “surgery”. You need to separate the screen from the main chassis. You can still open it up, but the process it a bit more involved as there are no screws to gain access inside. Unlike like most of the Windows PCs I worked on during my IT career, you can’t just simply open up an iMac and swap out the hard drive. If you want to read more about Fusion Drives, checkout this wikipedia link: These 2 drives appear and act as one volume on your iMac and the system takes care of moving/caching your most frequently used files onto the faster SSD drive. My iMac 27 Late 2013 had the Fusion drive which is basically a 1TB Seagate Hard Drive paired with a 128GB SSD Drive(for the late 2015 iMac models Apple has reduced the size of the SSD drives to only 24GB for the 1TB combo). 🙁 I tried booting into Recovery Mode (turn power on and the hold Command + R) and running Disk Utility, but it was never able to repair the drive. On Cyber Monday, it finally it “Gave up the Ghost” as they say and would no longer boot. I was having some previous random issues on my iMac where Chrome would lock up and sometimes the whole system would lock up, But, I kept blaming it on the 50 – 60 tabs I usually had open in Chrome 😉 Well, I really wasn’t planning on doing an iFusion Hard Drive Replacement with SSD post, but my hard drive failed earlier this week!

2007 imac hard drive replacement