iMac Intel 21.5" EMC 2805 Logic Board Replacement

Step 1

With the hinge free to move, the iMac will be unbalanced and hard to work on. Repairs are fast and easy with an iMac service wedge, but can be completed without one.
If you are using the iFixit cardboard service wedge, follow these assembly directions to put it together.
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.
Be very careful not to touch the capacitor leads or any exposed solder joints on the back of the power supply. Only handle the board by the edges.

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.

roberttrevellyan - 19/09/17

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

Dan - 12/02/18

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.

jerrid_foiles - 31/03/19

Instead of using the wedge, I placed the iMac faced up with the top side (web cam) facing me while I ran the pizza roller around. It worked out great!

Sam Fung - 06/06/19

“All iMacs also come with a traditional hard drive” mine doesn’t!! it’s HDD bay is completely empty, no SATA cable or anything. I guess I’ll have to upgrade the PCIe SSD instead.

Chris Hughes - 10/11/19

There is no replacement glass for this model, it is part of the LCD and impossible to remove or replace- the entire LCD has to be replaced unfortunately if the glass is cracked or damaged. You will have to Google search for a replacement. Also be careful with some of the lock tight tork screws as I broke one of my screw mounts taking one out.

Phil Tesone - 18/01/21

I used this service wedge but also found it a very tight fit. The same stabilization can be achieved by using a big rolled up towel.

Ernst -

While this is a good instruction guide, I recommend to also look at OWC’s instruction video about drive installation, before starting the exercise. Those install videos are very detailed and useful.

Ernst -

Main advice: TAKE YOUR TIME with the pizza roller.

Make several passes, until you really feel like there's no more sticker in the way. Stay away from the camera though (approx. 1inch / 2.5cm on both sides). This will reduce the work left with the plastic card. Adhesive is really on the edge of the screen so there is absolutely no need to go any further than the recommended 1cm / 3/8inch depth.

Where are the sensitive parts?

Facing your iMac, imagine you're looking at a watch. There are antennas on 1, 2 and 4 o'clock. Do not insert any metal piece there (nor anywhere else, btw). Other than that AND the screen cables underneath the camera, not much danger.

Froggy Manny - 23/03/23

Step 2

Starting on the left of the display, near the power button, insert the iMac Opening Tool into the gap between the glass panel and the rear enclosure.
The hub on the iMac Opening Tool will keep you from pushing the wheel in too far. If using a different tool, insert no more than 3/8" into the display. Otherwise, you risk severing antenna cables and causing serious damage.

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.

Richard Cook - 15/02/19

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

Alan Digby - 24/06/20

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 :(

Nikolay - 30/06/20

This part of the exercise should be done with extreme patience. I took my sweet time with the opening tool, rolling it through the entire panel and enclosure gap over and over again, until I was very sure no parts were sticking together anymore. And when I thought I was I done, I decided to do it over again.

Ernst -

You can "warm up" the adhesive before try to cut it with the tool using a hair dryer. Heat the edges for about a minute, keep moving it so you don't cause stress in the glass. Also the above note.. use the tool and then the cards. Do not use a guitar pick or other objects as the thickness will cause you to break the front glass, which is a bonded part of the display (expensive).

Carl Schultz -

Merci pour ce conseil

bry nicolas -

Step 3

Use the tool like a pizza cutter—roll it along through the gap, and it will cut the foam adhesive through the center.
Be sure to always push with the handle behind the cutting wheel. If you pull, the wheel might get pulled out of the handle.
Run the tool up along the left side of the display.

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

Moreau - 15/04/17

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.

plasticpool - 08/12/20

Step 4

Continue running the tool up around the top left corner.

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.

phfoglia -

Step 5

Cut the adhesive along the top left of the display.

Step 6

Continue along the top of the display.
You may want to run the tool back and forth through what you've already cut a few times, to ensure you get as much of the adhesive separated as possible.

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

arisnordico - 22/01/15

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.

dv1977 - 24/01/15

I did all steps like this manuell but now the Display wont work only some colered strips are to see! Whats happend??

Can anybody help me ? Maybe the connector cable is broken?

djfanta - 28/05/15

Check both connectors, probably one of them not seated well

pzhivulin - 12/06/15

You can add a SATA SSD if you already have a PCIe SSD Factory?

kaserlik - 30/05/15

If you're changing cracked EMC 2638 display to new assembly, there's two more steps:

Step 24: Use the tip of a spudger to flip up the metal retaining bracket on the display data cable.

Carefully pull the display data cable from its socket on the display assembly.

Step 25: Use the tip of a spudger to unplug bracket of the thermal sensor small cable near display data cable.

Carefully remove scotch tape covering thermal sensor. Using iSesamo or flat tip of the spudger carefully peel the thermal sensor away.

pzhivulin - 12/06/15

omg - forgot to switch the termal sensor from the old display...

now fan runs like crazy...

Andrei Balotescu - 05/02/16

The key thing is to never put any force on the opening tool when working through the tape. Just roll it back and forth with ease.

Ernst -

Step 7

Push the tool around the top right corner of the display.

Step 8

Wheel the tool down along the right side of the display.

Step 9

Finish pushing the opening tool to the bottom of the right side of the display.
At this point, you'll want to run the tool back around the entire display, to ensure you cut as much adhesive as possible.

Yes, do it many times to loosen the adhesive.

Noah Ralston - 19/07/18

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.

Carl Schultz -

Step 10

While the opening tool cut most of the adhesive, the display will still be slightly adhered to the case. A plastic card will be necessary to free up the last of this adhesive.
Set the iMac face-up on a table.
Starting from the top right corner of the iMac, wedge a plastic card between the display and frame.
Be careful not to insert the plastic card more than 3/8", or you may damage internal components.

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

Edgar Broekema - 18/11/17

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

Max Romano - 27/09/20

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

Morgana Devina - 30/10/20

@ifixit The next batch of cards you create should have a line printed on the card 3/8” in from the edges. Would make a nice reference.

Richard Giratd -

Here’s where OWC provides glass removal suction cups, which is a better solution than plastic cards.

The suction cups help to easily lift the glass panel, without risking the damaging of any internal wiring that the plastic cards could cause.

Ernst -

Better to remove stand wedge at this point? Can’t see from pics

derekrobinson -

Step 11

Gently twist the plastic card sideways to create a gap between the display and frame.
Move slowly and be careful not to stress the display glass too much—you only need to make a gap of about 1/4".

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

Cassio Machado - 17/09/16

Step 12

Slide the card toward the center of the display to cut any of the remaining adhesive along the top right corner of the iMac.
Be sure to stop before the iSight camera, or you may damage it.

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.

Felix - 31/05/20

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

Ernst -

Step 13

Wedge the plastic card into the top right corner once again, and leave it there to prevent the adhesive from resticking.

Step 14

Insert a second plastic card into the gap between the display and frame near the top left corner of the iMac.

Step 15

Gently twist the card upward, slightly increasing the space between the display and frame.
As with the other side, twist slowly to allow the adhesive time to separate, and be careful not to over-stress the display glass.

Step 16

Slide the plastic card toward the center, again stopping just before the iSight camera.

Step 17

Wedge the plastic card back into the top left corner.

Step 18

With both plastic cards inserted as shown near the corners, gently twist the cards sideways to increase the gap between display and case.
If there are any sections that seem to stick and won't separate, stop twisting and use one of the cards to cut the remaining adhesive.
Begin to lift the top of the display up from the frame.
Only lift the display a few inches—the display data and power cables are still connected to the logic board.

Step 19

Use a pair of tweezers to flip up the metal retaining bracket on the display data cable.
Carefully pull the display data cable from its socket on the logic board.
Be sure to pull the display data cable connector straight out of its socket.

Does anyone know where to find a replacement display cable for the 2014?

PN: 923-00047

PBMedic is out of stock

Brian Hernandez - 06/01/21

Step 20

While holding the display up with one hand, use the other hand to unplug the display power cable.
Lift the display up enough to have easy access to the connector, but not so much that you stretch the cables and stress their connections (about 8").

Step 21

Lift the display up to a near-vertical position.
At this point there is still a strip of adhesive along the bottom of the display, that will hold the display to the frame like a hinge. You can loosen this adhesive by working the display up and down a few times.

Step 22

Be very careful not to touch the capacitor leads or any exposed solder joints on the back of the power supply (boxed in red).
Grasp the small tab at the end of one of the bottom edge display adhesive strips and pull the adhesive toward the top of the iMac to remove it.
Repeat this step with the other adhesive strip and remove it.
If either adhesive strip breaks before it's removed, use a plastic card to slice through the remaining adhesive.

Anyone else notice this iMac is different than the one in Step 20. The cables are in different places. I just saw one on YT like this, in a different country.

Thomas Tommy -

Step 23

Lift the display up from the frame and remove it from the iMac.
It may be necessary to slowly lift from one side, to peel against the remaining adhesive.
Be very careful handling the display—it's big, heavy, and made of glass.
If you're replacing the display with a new one, you may need to transfer some components from the old display to the new display.
During reassembly, head over to our display adhesive guide to install the new adhesive.

Step 24

Remove the following five Phillips screws holding the lower support bracket in place:
Four 3.2 mm screws
One 1.7 mm screw
On at least some EMC 2544 machines, all five screws are the same size.
You may need to peel up the display adhesive lining the bottom edge of the iMac enclosure to access the screws.

I used the CR-V 4.0 standard screwdriver head to help peel away the adhesive lining. My fingers were too big to grab it, and my fingernails too short to get the removal started. This 4 screw head worked perfectly.

airshack - 07/02/20

Step 25

Remove the lower support bracket from the iMac enclosure.

Of all the parts of this entire procedure, replacing this one piece is the hardest part! The screws are tiny and they just don’t seem to want to grab the support piece. Also it seems to perform no function which is also annoying.

John M - 25/01/19

I left mine out. LOL

jerrid_foiles - 04/05/19

Line up the screw holes and press on the bracket from the back to help the screws grab. If your fingers are too big, press with the flat side of your spudger. As long as there’s no gap between the bracket and the iMac’s frame, the screws should grab easily.

Jeff Suovanen - 07/05/19

I put it in at a slight angle lining up the right hand side holes, screwed in the two screws and gently pressed my finger behind it on the rest

jmorphett5 - 30/04/20

If you only want to replace the HD and RAM, take a big shortcut and leave the logic board in, as well as all the parts needed to remove it (speaker, power supply etc). Once the display is removed, just take out the fan and the top two logic board screw. There is than sufficient space to gently remove and insert the two ram modules. HD can easily be replaced with an SSD by just removing the HD mounting brackets...

diddl14 -

Voces mudaram de modelo iMac, desta foto para proxima, esse modelo desta foto nao tem slot nvme. O da proxima foto sim. Voces me fizeram comprar un nvme por engano...

tgb4rr0s tege -

Step 26

Use the tip of a spudger to push on either side of the right speaker cable connector to walk it out of its socket on the logic board.

Step 27

Remove the two 10.0 mm T10 screws securing the right speaker to the rear enclosure.

Step 28

Insert the tip of a spudger between the right speaker and the antenna cable that is routed into the speaker's right side.
Run the spudger down along the right side of the speaker to pry the antenna cable from its channel in the right speaker.
If the channel is not easily accessible, you can pull the speaker gently away from the case to gain access to the antenna cable.

Step 29

Lift the right speaker straight up and remove it from the iMac.
It may be helpful to tip the top of the speaker away from the rear enclosure when removing it from the iMac.

Step 30

Remove the following screws securing the hard drive bracket to the rear enclosure:
Two 21 mm T10 Torx screws from the left-hand hard drive bracket.
One 9 mm T10 Torx screw.
One 27 mm T10 Torx screw.

Pay attention to this photo and where the fan is. It is 180° from where the previous step shows it is oriented to you.

Max Romano - 27/09/20

Step 31

Remove the left and right hard drive brackets from the iMac.

Step 32

The next few steps bring your hands close to the exposed face of the power supply. Do not touch the face of the power supply or any of the exposed solder. Touching it risks a high voltage shock from the many large capacitors attached to the board.
Use the tip of a spudger to push each side of the power button cable connector and gently walk it out of its socket.

I would advise that before removing the PSU unit and all other components from the bottom of the case that you remove the 5 screws at the bottom of the display which hold an insulation strip in place.

The guide shows this piece removed, but does not tell you how to remove it.

There will be 5, small J1000 screws. The middle one, which goes over Apple Logo is the shorter one of the 5, all others are the same length. Once this piece is gone removing the components is much easier, and chance of damage lessened.

[deleted] - 16/01/16

Added to the guide. Thanks for the tip!

Jeff Suovanen - 06/07/16

No need to remove power board and logic board and all other components, just remove the fan and it is quite "easily" accessable to change the RAM. Just need to use the tools to remove the old RAM and carefully install the new RAM.

I just did it without removing the logic or power board

Oleksandr Trokhymchuk - 11/08/17

could you elaborate a little more, I would love to skip the rest of these steps. How did you accomplish this?

ej P - 03/07/18

Oleksandr Trokhymchuk,

Thank you! You just saved me so much time! I wouldn’t call this “easy” but it saved me a lot of time and effort.

Joshua Ericson -

ej P: remove the fan assembly first. Then remove the connector that runs from the iSight camera to the logic board on the left.

the RAM is located right near that cable. It’s tricky to remove but you can pop open the connectors with a black nylon stick and the RAM chip will pop up at 45 degrees. Make a mental note on which way you will need to install the new ram as it’s tough to see. For the Crucial memory I got it was label side facing away you (facing towards rear metal enclosure).

the second chip has a plastic adhesive piece on it that you should probably attach to the new ram.

remove both chips then install the new ram in sequence from the board out.

Wizdom On Wheels - 10/07/19

In the photo for Step 28, the power button cable connector is placed around the power board screw hole on the top left of the power board.

However, on the iMac I upgraded, the power button cable connector was “fed” through the power power screw hole on the top left of the power board. The cable was too short to run around and below the hole.

Hence, I had to ensure the cable was “fed” through the hole during re-assembly and the screw carefully screwed back through the hole.

I guess every iMac is assembly just a bit differently, just to make repairs that much more fun.

Tim Telcik - 01/09/19

This is not correct and may have been assembled incorrectly during a previous repair.

Charlie Nancarrow -

Just replaced the hard drive and RAM with SSD and 16GB respectively and did NOT remove the power supply or logic board. Tricky is a word to describe putting the RAM in without removing the logic board. You work in the dark with little room to get your fingers in between the logic board and the back of the case. I put the first RAM chip in without a problem (the one next to the logic board), but the second to four tries and dropped it behind the logic board three times before finally getting it to position correctly. Just impossible to see and must work but feel. Still it was faster than removing all the components… though did remove the fan (needed cleaning anyway). All in all I can’t say enough about the help the guide was through the upgrade ! Thanks !

Ray Burgard - 14/12/19

I found this connector to be very tight and was afraid of breaking it off. I just kept slowly working on it—it did eventually come out.

I did try to sneak the RAM in without removing the logic board but my fingers were too big. I found it too difficult and just continued on with this guide.

Mikkif - 30/03/20

I was not able to install the memory without removing all the components. My fingers are too big and I could barely get in that tight spot to swap out the memory. The hardest part about the power supply is that one connector under the chin next to the Apple logo. Once it is out, you are home free because it is so easy to plug it back in when you are putting it all back together again. Ridiculous that Apple did not put a simple access door behind those memory slots because they are on the backside of the Mac! They did an access door on the PowerBooks and it did not ruin the appearance. They could have designed a cool looking pop out door that only had a thin seam around it so it would still look good. Then you could remove the access door to upgrade the memory easily.

Peter Hillman - 18/10/20

Does anyone know if this is the same situation as in the 2017 model? I just changed RAM in the 2017 version and also skipped taking out the logic board. I just bent a pair of tweezers and put some tape around the tips to make them less scratchy and used them to place the RAM modules into the slots. Worked supereasy and much much quicker than performing the complete tear down of the whole machine.

Nils Witte - 26/12/20

This step is impossible!

Cecily Walker - 05/01/21

@wizdomonwheels, I don’t see how I can get the RAM shield off of the logic board to access the RAM without removing the logic board. What am I missing?? I’m guessing that those of you that are suggesting this technique are working on older iMac models that don’t have the RAM shield.

jiclark - 11/03/21

Yes, you are correct. It is likely the various steps are a bit different on each model. If I recall I was likely working on a 2015 or older system. If there’s a shield in the way, I can’t think of a way you could get around it without pulling the logic board.

Wizdom On Wheels - 12/03/21

Step 33

Use the tip of a spudger to push each side of the power supply control cable connector and gently walk it out of its socket.

Step 34

Remove the two 7.2 mm T10 Torx screws securing the power supply to the rear enclosure.
In newer model iMacs these are 7.2 mm T8 Torx screws.
During reassembly, be careful not to trap the power button wire behind the board.

In my case, the left side corner of the PS was caught against the Lower Support Bracket, and I had to remove the LSB in order to get the PS freed and out.

I think the author Walter Galan should put this in the main section of his instructions. I have TWO identical iMac 14,1 / i5 2.7GHz / 21 Inch Late 2013 / Order ME086LL/A. They both required removing the LSB. Thank you very much Walter Galan & others for your contributions.

Ted Horodynsky - 15/07/20

Those screws were definitely not T10 but T9 on my unit

Vincent Monteil - 27/12/20

Those screws were T8 on my unit.

jag32mobile - 17/01/21

c'est du torx 08

pascal cacou -

Step 35

When working on the power supply, be very careful not to touch the capacitor leads or any exposed solder joints on the back of the power supply. Only handle the board by the edges.
Tilt the power supply forward.

When replacing the PSU (on the re-build) take care not to trap the power button cable behind it - I did...

Dave Hallett - 10/08/17

Step 36

Pull the power supply slightly up and out from the rear enclosure.
Rotate the power supply counterclockwise, lifting the right side up about an inch higher than the left.

In my case, the left side corner of the PS was caught against the Lower Support Bracket, and I had to remove the LSB in order to get the PS freed and out.

I think the author Walter Galan should put this in the main section of his instructions. I have TWO identical iMac 14,1 / i5 2.7GHz / 21 Inch Late 2013 / Order ME086LL/A. They both required removing the LSB. Thank you very much Walter Galan & others for your contributions.

Ted Horodynsky - 15/07/20

Step 37

Slide the power supply to the right to clear the screw posts on the rear enclosure.

Step 38

Rock the power supply forward and remove it from its recess in the rear enclosure.
Do not try to completely remove the power supply from the iMac yet—it is still connected to the logic board.

Step 39

Be very careful not to touch the capacitor leads or any exposed solder joints on the back of the power supply. Only handle the board by the edges.
Flip the power supply over to access the DC power cable connection behind the logic board.
Squeeze the tab on the back side of the DC power cable connector and pull it straight out of its socket on the back of the logic board.

when pulled the cable, even slightly, the actual female piece that connects to the logic board came off. am i screwed?

Racheal Major - 08/05/17

Repairing sockets that come off the logic board is possible, but very specialised work. Unless you have a magnifying lamp and the necessary desoldering and soldering skills, it will be difficult but not impossible.

Charlie Nancarrow - 28/07/19

The tab is at the far end of the connector, so you’ll need to reach farther than you might think.

lkollar - 30/12/19

When I pulled the disconnect, I pushed down on the disconnect, instead of pushing down on the tab on the disconnect and bent those pins… tried to straighten the bent pins and two of the pins broke off the logic board. Will I need a new logic board or can I purchase the pins…?

Ray AA - 04/06/20

I could not disconnect this cable without fear of breaking something (as previous posters did). I found that I could skip this and the next step by wrapping the power supply in a couple layers of a small towel (to prevent shorting with any other metal surfaces), and laying the power supply on the aluminum face of the iMac near the Apple logo. This got it out of the way enough to do what I needed on the logic board (changing PRAM battery) after completing removal of the other items in this guide.

Phil McInnis -

Step 40

You may find it helpful to set the iMac down on its back for the next couple of steps.
Use the flat end of a spudger to press the clip on the side of the AC inlet cable connector inward.
While pressing on the release clip with the spudger, grasp the AC inlet cable, and pull the connector straight out of its socket.

I didn't disconnect the input cable to the power supply. Because I had the machine lying on its back throughout, I placed it on to the metal bit at the bottom of the machine instead (with a cloth to stop the metal getting scratched). The AC inlet cable was pretty tricky to get un-locked, and the PSU sat on the case fine. It didn't hinder anything else throughout the guide.

Dave Hallett - 10/08/17

I thought from Dave’s comment that I could leave the power supply completely in place, but I was mistaken. In order to remove the hard drive assembly after you remove the center screw in it, you’ll need to at least unscrew it and the HD assembly will slip out. Like Dave said, you don’t need to unplug the AC or PSU, which I left hanging.

Getting power supply to the logic board unplugged is also tricky without unscrewing the two bottom screws. They didn’t make this part easy.

delacrj2 - 22/12/17

Kleiner Rechtschreibfehler - statt „denac“ muss es wohl „den iMac“ heißen

Gonzalo - 01/11/18

Au ja. Du kannst so was selbst ausbessern. Einfach auf “Übersetzen" gehen und loslegen.

VauWeh - 01/11/18

I would like to thanks Dave Hallett for his tip of not removing the AC inlet connector of the power supply. I simply wrapped the board in bubble wrap and taped to the iMac case, out of the way, thus giving access to the remaining disconnection procedures and preventing the board from scratching to the iMac case. It also made reassembly much simpler.

Rob Hogan - 04/08/20

Yeah, that AC inlet plug was a nasty one to unplug, mainly because I was trying not to bump the solder joints on the PSU. After a few wiggles and pulls while manipulating the spudger tool to release the clip, it finally unplugged. Made it easier by removing the PSU completely so you don’t have to worry about it. Don’t worry, plugging it back in is a breeze!

Peter Hillman - 18/10/20

With the right tool this plug comes out very easily. Forget about your tiny computer tools, go to the garage and grab a regular old needle nose pliers. Grab the clip and the plug at the same time. The plug will come right out.

Carin Ann Loewen - 08/03/21

Carin Ann— The most helpful comment on this procedure. After reading what you wrote I maneuvered the board, grabbed the clip with my left hand (a little awkward because of the cooling enclosure), squeezed the front of the plug, and got it out.

Glen Kohler -

+1 for needle nose pliers!

Sam -

Step 41

Remove the power supply from the iMac.

erreur: retirer "la carte d'alimentation" et non" le disque dur" !!!!!

Moreau - 16/04/17

Step 42

Use the tip of a spudger to push the fan cable connector out of its socket on the logic board.
It is recommended to carefully push on both sides of the connector to walk it out of its socket.

Step 43

Remove the following screws securing the fan to the rear enclosure:
Two 12.5 mm T10 screws
One 9.9 mm T10 screw

Step 44

Lift and remove the fan from the iMac.

Step 45

Lift the hard drive from the edge nearest the logic board and pull it slightly out of its recess.
The hard drive is attached by a single SATA power/data cable—do not attempt to fully remove it from the iMac yet.

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

Carl Schultz -

Step 46

Use a spudger to disconnect the single SATA power and data combo cable by gently prying its large plastic connector away from the hard drive.

When reconnecting the SATA cable, there is nothing to make the connector hold still, and it is hard to reach, so it took several tries. I ended up taking off the rubber baby buggy bumpers to get more room, and then jamming them back on after getting the SATA connector snugged up.

bstaud - 28/03/18

If by rubber baby buggy bumper, you mean left speaker, then yes, I agree. Reinstall the hard drive before the left speaker.

jerrid_foiles - 31/03/19

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!!

jiclark - 11/07/19

We solved this by removing the hard drive tray screw, then inserting the cable into the SATA hard drive. Then hold the hard drive a bit out of the way to insert the 7.3mm hard drive tray screw.

Marjie - 25/07/19

Agree with this method, found it an impossible task to reconnect the SATA connector until removed the tray screw, then it was relatively easy to reconnect and then replace the tray screw.

daveedwards - 20/09/19

Also agree with this method!

jmorphett5 - 30/04/20

Step 47

Remove the hard drive assembly from the iMac.

When reassembling, I found it easier to loosen the HD tray screw from Step 48 and pull the tray outwards from the left side in order to plug the SATA cable in more easily.

Cool_Breeze - 10/05/17

Thanks! I, too, had a hard time reconnecting the SATA cable.

boboswell - 16/06/17

I found this helpful too!

Anwar - 07/02/21

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

bsmith1 - 15/12/17

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.

Noah Ralston - 19/07/18

I found the easiest way to connect the SATA cable was to not screw the plastic hard drive tray down until you plug the drive in. That way you can easily push the connector in and due to the cable you’ve got some wiggle room. You can position the tray then just lift one end of the drive up and secure the screw. Then just push the drive down.

Chris Caldwell - 21/03/19

This was the step that I had the most trouble with. I’m used to replacing a hard drive in a MacBook Pro, where the “plug” that you plug the drive into is a rigid thing that you can firmly press the hard drive into.

With the iMac, the plug is situated on the end of a non-rigid cord, so the plug moves back when you try to snap a drive into it. Also, those two rubber gasket things that you adhere to the side of the drive really make it difficult to maneuver the now-overly-chubby drive towards the plug.

After must frustration/concern, what I ended up doing was temporarily removing the rubber gasket things, using the “spudger” as kind of a lever behind the “plug on a cord” so that it didn’t move as much, and then pushed the gasket-less SSD into the plug.

Once I got it connected, I put the rubber gaskets back on the sides of the SSD and kind of coaxed it down into place, using the pointy end of the spudger to get the chubby corner pieces to “sit” correctly in the rigid plastic tray that the SSD kind of rests in.

Jack OnFlickr - 29/05/19

From another comment elsewhere on this repair, I *highly* recommend removing the two screws holding the left speaker in place, then sliding it just a tad out of the way to be able to easily attach the SATA cable. You don’t have to move it much to make the whole process so much easier!

jiclark - 11/07/19

Step 48

Remove the single 7.2 mm T10 screw securing the hard drive tray to the rear enclosure.

HD Screw is a T9 on mine

TheStudioDrummer -

Step 49

Remove the hard drive tray from the rear enclosure.

You will have to reroute the sata cable beneath too. The drive tray will not simply lift out.

biscuit - 04/02/17

Step 50

Use the tip of a spudger to walk the left speaker cable connector out of its socket.
It is recommended to first press on one side of the connector, then press on the other side until freed.

Step 51

De-route the left speaker cable by pulling it straight up out of the retaining clip in the back of the rear enclosure.

Step 52

In a similar fashion as the previous step, de-route the combo SATA data/power cable up out of the retaining clip.

Step 53

Use a pair of tweezers to flip up the metal retaining bracket on the iSight camera cable connector.
Pull the iSight camera cable straight out of its socket on the logic board.
This is a delicate connector that can be easily damaged.

Step 54

If necessary, use the tip of a spudger to peel back the tabs covering the antenna connectors.

Step 55

Use the tip of a spudger to disconnect each of the four antenna connectors from the AirPort/Bluetooth card.
Note the original positions for each connector when reconnecting the cables.

Step 56

Use the flat edge of a spudger to pry the headphone jack cable connector from its socket on the logic board.
Push the cable slightly to the right.

Step 57

Remove the following screws securing the exhaust duct to the rear enclosure:
Two 6.3 mm T8 screws
Two 4.7 mm T8 screws

Step 58

Remove the four 7.2 mm T10 screws securing the logic board to the rear enclosure.

Step 59

Use a pair of tweezers to peel the tape covering the exhaust duct.

Step 60

Tilt the top of the logic board away from the rear enclosure.

Step 61

Lift the logic board straight up and out of the iMac.
Be careful not to snag the board on any of the rear case's screw posts.
The I/O inputs at the bottom of the logic board will be the greatest challenge. It is recommended to pull gently to avoid any damage.

Step 62

When reinstalling the logic board, check the alignment of the exterior I/O ports. The logic board can sit crooked even when secured with all its screws.
Use a USB flash drive and/or ethernet cable to keep the logic board aligned while you screw it in.

Step 63

The SATA data connector has a clip that must be pressed to allow removal.
While pressing on the clip with your thumb, lift and disconnect the SATA data connector from its socket on the logic board.

If you’re only replacing the PRAM battery, you can access the battery without removing the SATAdata and power cables.

Kenneth Jackson - 26/10/20

Step 64

Grasp the hard drive power connector and gently pull it out of its socket on the logic board.

Step 65

The following screws secure the heat sink to the logic board:
Remove the two T8 screws from the exhaust port end of the heat sink.
Loosen, but do not remove, the four captive T8 screws securing the CPU end of the heat sink.

Step 66

Slowly lift and remove the heat sink from the logic board.
When reassembling your iMac, follow our thermal paste application guide to reapply the thermal paste.

Step 67

Remove the two 3.2 mm T5 screws securing the AirPort/Bluetooth card to the logic board.

Step 68

Slightly lift the AirPort/Bluetooth card and pull it straight out its socket.
Do not use excessive force to pull the end of the AirPort/Bluetooth Card away from its socket on the logic board. Doing so may cause severe damage.
When reinstalling the card, be sure it is properly seated before reinstalling the retaining screws.

Step 69

During reassembly of the logic board, pay attention to the position of the I/O connectors. When the board is back in the case, insert a USB or Thunderbolt cable into one of the connectors to align it perfectly.

iMac Intel 21.5" EMC 2805 Logic Board Replacement

Introduction

Tools

Parts

0 comments