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It may sound like a silly question but please bear with me. I’ve managed to get my hands on a brand NEW unopened 21.5” 2017 4K iMac (featuring a fusion drive) and would like to perform a full system upgrade (blade SSD, 2.5” SSD and RAM) before even turning it on for the first time. My question concerns installing a fresh copy of MacOS on a system upgraded as such. Would I need to create a bootable drive before hand (basically turn the system on first)? Or does the Internet Recovery feature exist within the BIOS?
There is no difference between a virgin unused system Vs turned on a few times. So you are panicking over nothing here. I would start it up before I do anything to make sure the system is even working. Let’s say your system was bad and you didn’t even try turning it on you would go nuts trying to find a problem you created (which you didn’t). Now with that said… I would do the RAM and blade SSD first as both require talking the logic board out. But before you do that you’ll need to break the Fusion Drive set first so your SSD is not magically engaged into the Fusion Drive cache drive with the current HDD. Given how much work it is to get this deep I strongly recommend you stick with either real Apple blade SSD or OWC SSD. Review this guides and follow them to the letter and use the tools listed: iMac Intel 21.5" Retina 4K Display (2017) Blade SSD ReplacementiMac Intel 21.5" Retina 4K Display (2017) RAM Replacement And here’s the guide for replacing the HDD for a SSD: iMac Intel 21.5" Retina 4K Display (2017) Hard Drive Replacement Don’t forget to get a few tape sets This kit has all of the needed tools iMac Intel 21.5" (Late 2012-2019) SSD Upgrade Kit
