iMac Intel 21.5" Retina 4K Display (2017) CPU Replacement

The wedge is an extremely tight fit for this model. I was worried that the amount of force needed to use it as shown might damage the stand, so I used it with the long side down instead. It worked fine that way and didn’t need anywhere near as much force to insert.

Here’s a good YouTube vid on upgrading the RAM: Can a Normal Person Upgrade the RAM in the 2017 21.5" iMac?

Here are a couple tips from me:

1) Expose the adhesive to extreme temperatures. I did this by transporting my iMac in my car, screen-down on a piece of cardboard on a cold February morning (in Chicago). When I went to pick up the iMac, the screen practically fell off the chassis. I would have been distraught by this if I hadn’t already planned this replacement. So it was a happy accident.

2) Remember to expell the residual power from the power supply by pushing the power button while the iMac is unplugged. This does NOT guarantee it’s safe to touch, but when I accidentally brushed the solder and exposed capacitors, I didn’t get shocked.

Don’t get too worried about starting exactly where the picture says. The glue is stronger in some parts so just start wherever is easier and then work slowly and patiently around in the direction shown.

As this guide doesn’t cover replacing the adhesive strips, I found referring to the following was useful (noting that it’s not for the same model of iMac, so the modification they mention wasn’t necessary): iMac Intel 21.5" EMC 2544 Adhesive Strips Replacement

It is very easy to crack the glass in front of the LCD during this step. I used the guitar pick, maybe it was too thick… crack is just on the frame but anyway it is disappointing :(

Erreur de traduction: "de bas en haut" et non de" haut en bas" sur le côté gauche de l'écran

If re-opening a screen that was opened and re-attached using iFixit’s adhesive strips, I would strongly recommend heating it first with an iOpener, heat gun or hair dryer. 20 minutes after attaching with the iFixit adhesive I tried to open it again with the pizza slicer to fix something and cracked the screen on the left-hand side.

Ne pincez pas l’écran avec l’autre main. Vous exercez une pression inutile sur le verre et empêchez la roulette de couper le joint.

In this step can I cut along the display without make any damage to the front camera?

Hi! Actually - there is no need to cut the tape around the camera area - there is no tape to cut at all! And so, the way go is easy - just pass 10 mm to the left and to the right from camera and start cutting!

P.S. Just did the whole procedure to replace a RAM and to add SSD on PSIe an hour ago! Seems to be different reading the instructions... you know - 2/10 and so on. But it's really not that hard, trust me. I'll give it 5/10.

P.P.S. By the way there is one trick to pass the difficult steps. Any action which requires pulling smth (motherboard, speaker, power supply unit) from the narrow crack (or should i say - slit?) at the bottom of your Imac is really not so easy.

And the trick is to first remove a thin metal stripe with some kind of insulation on it which held by 5 small (very small!!) screws at the bottom of your Imac. After you done it - it's easy to pull everything! Pay attention to the fact that one of this 5 screws at the center are more shortly than others.

Yes, do it many times to loosen the adhesive.

Would be good data to show the 3 areas (wifi antennas where the "tape" is larger and covers them. The rest of the "tape" is 1.4" and easy. Also after removing the display, be sure to remove the old "tape" from both the display and the rubber parts of the case. Use the spudger to start an end and it should pull off easily. Careful on the baackside of the display as you can scratch off the black paint/covering.

this step is extremely important NOT to stick in the cards too far….. doing so, you risk a 600 euro replacement as I experienced………

I drew a 3/8” line on my cards with a marker first.

I’m reading this on the EU store, please change all measurements to cm/mm.

This part must be done very carefully or you can damage the flat cable from display, despite it was under a iron cover.

You don't need to do it like this, simply open the iMac bendidng the LCD completely and use the pizza cutter to remove the adhesive.

Using glass removal suction cups will avoid running this risk of damaging the camera (or any wiring).

It was difficult to remove this connection. I ended up having to gently pull-up vertically a little on the wire side to unsnap it about 1mm and then horizontally wiggle it out.

I had a difficult time removing this connection. I had to lift the wire-side about 1mm before it unsnapped and then carefully wiggle it out horizontally.

Can this cable be replaced? I am worried mine is damaged. I have no display after the screen fell and stressed the display flex cables following an SSD upgrade.

I also need that cable.

It's a little difficult to tell... but looking at the connection to the logic board on the video data cable, are the pins faced up or down?

On the display, same question since it appears you have to "twist" the cable during the reconnection step.

The best way to remove the chin adhesive is to use the tabs at either end (there are two strips that run from each outside corner to near the centre). Carefully pull the tabs up and the strips should peel off.

At step 21-22, releasing the adhesive strips from the bottom of the display, I noticed a tab on the outer end of each strip. Pull the tab to remove the whole strip, no need to mess around with the plastic cards!

Instead of the plastic cards, use the flat end of a spudger. Use it as scraper. Be careful as there are antennas mounted on the inside edge of the frame on the right side (facing you), and the top right (facing you). The original adhesive strips are on those as well. - ECJ

A little bit of hot air (eg. hair dryer) will help soften the adhesive. Use a piece of cardboard or equivalent if you want to avoid blowing hot air towards the electronics.

Be careful to remove absolutely everything - any remainder will create a bump and prevent your screen from sticking back to the frame when reassembling.

I would recommend that those trying this have the project tray to contain all of the screws.

2 notes for reassembly, carful with screws not to strip the heads as they are really really small, make note to cut a gap in the the adhesive over the whole for the microphone.

I managed to strip the head of one of the screws when putting it back in. So be carful with them when putting in / taking out. If you strip it on the way out you will need to take a fine drill and rill it out. Going back in, well as long as you never need to strip it down again not a problem.

The second problem is a real pain, you need to make sure to cut a gap in the adhesive just to the right of Center at the button to allow for the microphone opening. If you don’t, the adhesive tape will stop any real pick up on the Mic, so you just need to cut a small gap in it before putting on the screen. Unfortunately I didn’t find this out (or do my checked before sticking it all back down, so have to pull screen back off and reapply new adhesive with a cut out in it at an other time.

Refer her for more info on the mic / adhesive work around —> Muffled Microphone - iMac 21.5" (mid 2017) - Following Adhesive Strips

Keep this long, aluminium part very straight when pulling it away or you might bend it

At step 26, when reassembling, it's super easy to over-tighten the 9mm screw and strip the brass ferrule out of its hole in the plastic bracket (%#*@).

Mine has 4 different length screws, the two red colored 21mm screws in this guide are actually two differ lengths

Mi imac does not have a HDrive whats the steps to follow?

I didn't bother to remover the power supply lead in this stage but simply flippedthe circuit board over onto the lower body of the iMac (NOT placing it directly onto the metal but onto a sheet of plastic)

The newer drives have rubber ends and an adhesive side, be careful removing them if replacing the drive and be sure they are securely pushed back into the holder

Kudo to @jerrid_foiles! I was going crazy trying to attach the SATA cable until I took the two screws out of the left speaker and slid the top end of it aside by about 3/4 inch. Make the whole process SO MUCH easier!!

And DON’T do what I did, which is to remove the left speaker - which can easily lead to breaking the cable between the power on button and the power supply. The cable is routed through a hidden slot at the very bottom of the left speaker

I did loosen the speaker so I could get a tool behind the SATA cable to push it on to the SSD drive. Otherwise hard to align cable.

it`s a t10 screw..! ;)

I found it easier to connect SATA cable before fixing tray.

I am following these procedures for the following: iMac Retina 4K - 21.5" - 3GHz Quad Core - Radeon Pro 555 2GB - 4GB/4GB (8GB total - 2 slots) 2400MHz DDR4 SO-DIMM - Mid 2017 - Model: MNDY2LL/A - iMac18,2 - A1418 - 3069. In my case, the SATA cable is clipped into the bottom of the hard drive tray. Pull the hard drive tray up slightly and angle to reveal clips. SATA cable pops out from the side of each clip.

Better yet, after reading Step 49 - no need to remove SATA cable from the bottom of the hard drive tray.

When repairing, I accidentally broke a small piece of what it seems to be a resistor. Mac still works fine and diagnostics reports no errors. Be careful when removing the mother carefully so it doesn’t hit the aluminium cover.

Gibt es dafür passende Leitpads ?

Is it possible for the 21.5, 4K model to support/handle the i7-7700k processor?