Introduction
Use this guide to replace or upgrade the CPU in your 21.5" Retina 4K 2017 iMac.
Some images in this guide use a 2015 iMac, which has minor visual differences. These differences do not affect the repair procedure.
This guide is marked "potentially dangerous" because it requires you to handle a power supply that contains large capacitors. Unplug the iMac and hold the power button down for at least 10 seconds to help discharge the capacitors. Handle the board by the edges and do not touch surface components.
What you need
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Tool used on this step:iMac Intel 21.5" Cardboard Service Wedge$4.99
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Before beginning any work on your iMac: Unplug the computer and press and hold the power button for ten seconds to discharge the power supply's capacitors.
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Tool used on this step:Plastic Cards$2.99
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Starting from the top right corner of the iMac, wedge a plastic card between the display and frame.
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Hold the display with one hand while using your other hand to unplug the display power cable.
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Remove the following five Phillips screws holding the lower support bracket in place:
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Four 3.2 mm screws
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One 1.7 mm screw
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Remove the following T10 Torx screws securing the hard drive brackets to the iMac:
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Two 21 mm screws
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One 9 mm screw
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One 27 mm screw
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Use the tip of a spudger to push each side of the power button cable connector and gently walk it out of its socket.
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To disconnect the cable, squeeze the release clip on the back side of the connector, behind the logic board, and pull the connector straight out.
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Use the flat end of a spudger to press the release clip on the side of the AC inlet cable connector inward.
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While pressing on the release clip with the spudger, grasp the AC inlet cable, and pull the connector straight out of its socket.
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Lift the hard drive from the edge nearest the logic board and pull it slightly out of its recess.
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Remove the 7.3 mm T8 Torx screw securing the hard drive tray to the rear enclosure.
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Gently pull the left speaker cable straight out of its socket on the logic board.
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Use the tip of a spudger to flip open the retaining flap on the microphone ribbon cable ZIF socket.
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Gently pull the microphone ribbon cable straight out of its socket.
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While pressing on the clip with your thumb, lift and disconnect the SATA data connector from its socket on the logic board.
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Peel off the four black tamper-evident stickers covering the heat sink mounting screws.
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Remove the four T10 screws that secure the heat sink from the backside of the logic board.
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Flip the heat sink over and use your spudger to pry out the CPU, being careful not to drop it.
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Use a lint-free cloth (or coffee filter) with either isopropyl alcohol or ArctiClean Thermal Material Remover to thoroughly clean the thermal paste residue from both the CPU and GPU arms of the heat sink.
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Once the heat sink surfaces are completely clean, use a fresh lint-free cloth or coffee filter to apply a drop of ArctiClean Thermal Surface Purifier to remove any oils and prepare the copper heat sink surfaces.
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Allow the heat sink to dry completely while you continue working.
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Follow the instructions specific to your CPU type to apply fresh thermal paste to the surface of your CPU.
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To reassemble your device, follow these instructions in reverse order.
To reassemble your device, follow these instructions in reverse order.
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42 Comments
Can I upgrade to i7 7700K on iMac 2017 21.5inch ?
looking at the compare on intel’s website:
https://ark.intel.com/compare/97128,9712...
the 7700k being a 130w vs any Apple installed CPU being 65W, I’d think the the likelihood to overheat or draw too much power would be high but I don’t have enough experience to know for certain.
Benjamin -
Hey Mikkser, 8-series (Coffee Lake) CPUs require the Z370 chipset, which to my knowledge isn’t on the 2017 iMac logic boards. The socket is the same as the last generation so you’d be able to plug an 8700K in, but it wouldn’t work.
