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I got an iMac 27” 2017 model with 580PRO 8 gb… I’m wondering is there any chance to upgrade my logic board with the newer from iMac 27” 2019 model without changing the case and LCD? I saw some videos from disassembling the 2019 model, and the internals look pretty much the same. Isn’t it? Do I have to change the power supply as well?
Apple loves sticking with a theme! The external view often look the same across a model run from 2012 all the way to 2019 systems for both the 21.5” & 27” models But while the externals appear to be the same Apple tends to move things about tweaking this or that internally. So lets run down the major parts which Apple has manage to stick to for a few models in your 2017 system: 27” iMac Retina 5K Power Supply 300W used in the Late 2015 and 2017 models And that’s it! Here’s a full listing of common systems to yours: iMac18,3 the internal parts across all of these systems are the same. The logic board while the same size physically, is not laid out in the same way between the 2017 and 2019 models. So the cables that go to it are not the same locations and to add to it, Apple has also altered the signaling on some as well. As an example the display was upgraded from 2017 and 2019 systems which prohibits the use of the swapping the displays across the two series. So the TD;LR - Nope not possible!
In fact I just completed this same swap, switching a 2017 4.2 i7 logic board into a 2019 3.4 i5. The differences were very minor. The length of the backlight cable was slightly different, but yes, it did fit and it runs just fine!
