Reemplazo del disco duro del iMac Intel 27" EMC 2639

Removing the original adhesive is easier than removing newly applied adhesive (e.g., if you have to reopen iMac).  If you should happen to need to reopen the iMac, please use extreme caution and highly consider my suggestions below.

When using the pizza cutter tool, do the first few steps in reverse starting with step 8.  Starting on the left side is better since this is where the adhesive is narrowest.  The right side has two antennas and the top right has one, see the pictures for step 18-21, they are the brass colored metal rectangles near the edges.  The adhesive on these pieces are wider and therefore have more holding power.  The thickness of the pizza cutter tool is enough to crack the glass.

I would highly, highly, highly recommend AGAINST doing this at home. I followed these instructions to a T, and still somehow managed to have the screen not be able to turn on after the hard drive replacement. Then, once you’ve opened your Mac yourself, Apple will refuse to fix anything on the computer, and even other third party, Apple-authorized repair facility will refuse to repair it for you, and you will have to locate a non-authorized Apple repair facility. There, I am having to pay ~$600 to fix things that got screwed up, even though I followed the instructions here to a T, step by step, and did everything slowly and methodically.

Beware, if you’ve never done this before, that be locked out of ever being able to use an Apple repair facility, or Apple-authorized repair facility, if you mess things up here now.

First impressions so far: yes it can be a bit nerve wrecking if it is your first time doing this sort of thing and even with lots of experience with a 2011 model it’s still a bit unsettling haha (nervous laughter).

What I recommend: use a guitar pick to start cutting the glue. You’ll need a bit of pressure so do just the tip.

Once you’ve done the whole perimeter (minus bottom) do it again but now it should be easier to go deeper so go very slow and careful. Then get the old suction cups used to open older models and start lifting the display very carefully to see where it’s still glued and cut those as well.

Then you should be done and now the real fun begins! :D

It’s ridiculous. Apple should pay for doing this. Like glue parts together to block a repair / make difficult. I smashed my iMac. FU Apple. Seriously, every product I owned had hardware issues. For example, bad solder joints. Never again Apple. I’m happy with Windows and in 2018 / 2019 there are many other manufacturers with high quality stuff. Apple is dying, if they do not change …

NOTE: I followed every step word for word, but the adhesive strips supplied are as bad as double sided tape. Within 48hours the screen had slipped off and cracked. Now I need to fork out for a new screen and try again.

Not sure what to try next time with strips? Perhaps a bit of glue to help hold it??

After disconnecting the power cord and before cutting the panel adhesive, push and hold the power button for 10 seconds. This will discharge the power supply capacitors. In case you accidentally touch the solder joints on the board, you won't be shocked and drop the panel.

Just completed the Core i5 to i7 CPU upgrade and can strongly recommend getting the “pizza tool” to cut the display adhesive. It worked flawlessly and was done in less than 5 minutes. No inadvertent cables cut. No display problems.

Thank you very much for the tutorial. You are the best!

After reading all the post here I almost gave up doing this on my own. But I did it anyway and was succesful. I would recommend everyone to use the rollcutter. There is no risk of harming the screen if you use it. And in my case it was enough to open the imac. If you do not harm the screen connector or the screen the biggest part is done. It gets easier once you`ve stacked your screen somewhere safe. The parts inside are mostely not as delicate as the heavy and expensive screen!

Take your time and work carefully. It is definitely doable!

I found the 'pizza cutter' surprisingly smooth at cutting through four-year-old adhesive.

In my experience the cutter also worked very well for cutting the original adhesive. Unfortunately when I was reinstalling the display with the new adhesive strips, somehow the display power connector came loose. I had to open the display a second time and the cutter was not as effective against the new adhesive. I managed to break the cutter tool plastic wheel and cause a few small cracks in the edge of the displays glass as I worked! Be careful and go slowly!

The cutting tool worked great until I accidentally twisted it a bit while rounding a corner. A chunk of the wheel snapped off, making the rest of the job quite a bit more challenging. Just make sure you are keeping the tool directly parallel with the screen.

I concur, opening the screen a 2nd time is considerably more difficult because the adhesive strips are thinner than the original, which makes getting the cutting tool inserted much more difficult….as a result unknowingly I elongated a small crack to a much longer crack and somehow, the LCD now has a wide grey strip from top to bottom….The first time opening was easy, second time resulted in a ruined screen.. The cost of. a replacement LCD is the same has replacing the entire computer….I would recommend anyone attempting to remove the screen for any reason, do not use the aftermarket adhesive strips if you ever intend to open it up; again, or cut the strips much shorter, or possibly use a few pieces of scotch tape or similar to hold the screen in place….since the screen tilts back, this should not be a problem…Good luck…

The pizza cutter will sink in all the way to the tool handle when the adhesive is full cut, but don’t feel you have to do this in one motion. Some parts cut easier and some require a lot (like 20x) of gentle back and forth.

what about the part where the camera is though? do I just treat it like the rest of the screen?

yes. the tool can’t go too deep

I measured a depth several positions.

- About 6 centimeters near iSight Camera center, you must no use iMac opening tool, because iSight element exists.

- iMac opening tool has a 9mm radius, so it may break iSight camera element.

- Making a plastic card stacking 2 or 3 to 3mm, under the iMac opening tool, that makes inserting a gap 5~6mm like below.

@. iMac opening tool

====== plastic card3 (credit card 1mm)

====== plastic card2 (1mm)

====== platic card1. (1mm)

———————————————— isight camera element (total 5~6cm) ————

In my case, i got a display problem where lcd display yellow connector was torn without care.

Be helpful.

I actually DESTROYED my display (black vertical strips) by pushing the card in a bit TOO DEEP. So it is REALLY important to insert the card only a bit (1-2mm) more than the cutter wheel, in particular at the top side, where many flat cables connect the panel with the PCB. These can be damaged very easily!

Same thing with me…. Pushed cards to far…. new panel needed…€600…..

i think ifixit needs to place a bigger caveat, as I have missed it the first time

i successfully upgraded two imacs. one opened with ifixit pizza knife and another with a regular paper knife. however, when i had to open the first one once again i broke its screen glass. it seems ifixit adhesive strips are too strong. next time i’ll try to use heater to weaken glue tension.

I broke one too. And even if you think you did it correctly, you’ll not be able to see where you might have gone too far. You would think it’s very protected behind that metal plate, but no. Take special care with this offence to “right to repair” This should have been designed WAY better. I mean replacing a hardrive that is very likely to fail over the course of time, or even a simple desire to upgrade to an ssd!.

Bummer

I’m thinking I might just use vinyl tape to keep the screen in place for at least a little while after an upgrade. The extra strength of the replacement tape sounds scary.

Umm.. I’m not sure that I’d recommend using a repurposed credit card to open the display - I found that using the “pizza tool” to cut the old adhesive then using a pair of suction cups to gently pull the display up worked perfectly well.

The pizza roller tool is enough to cut through the adhesive. You dont need to cut in a lot further. So the cards are really not necessary.

My children tend to collect cards like this from hotels, Disneyland, old IDs, iTunes cards, gift cards etc. They came in handy for this step. After wedging in the first card into the left corner, I wedged the left corner, then added cards along the bottom edge. Finally I continued to push in additional cards to existing cards and found that this created a smooth even pressure along the display top. At 2-3 card-thickness the last of the adhesive let go, gentle as a baby.

was denn jetzt? Vor der Kamera aufhören, oder in Richtung Bildschirmmitte schieben, um DEN REST zu entfernen? Wenn ich vor der Kamera aufhöre, kann ich nicht alles an Kleber entfernen.

I would recommend using suction cups at this stage to lift the display.

I would strongly recommend using suction cups

Agreed about the suction cups. An extra pair of hands might be good here as well.

I agree, I’m using iFixit suction cups right now.

Go very slowly when lifting the display – give time for the adhesive at the bottom edge to stretch and flow. If you lift too fast, the glass can crack. That’s what happened for me.

The stickiest location on my iMac was the mid-to-lower section of the right side. There are a couple of thicker areas that needed attention from the plastic cards.

Mark all cable connectors with a spot of white correction fluid before removal. This will remove the risk, when reinserting them later, of getting them the wrong way round. Yes - I know they will only plug in one way round, but it does make life easier if you are not in perfect lighting!

At this step, if you mess up anything with these 2 cables, especially when plugging them back in, even if you think you’re following the instructions here to a T, then you’re screwed.

I would highly, highly, highly recommend AGAINST doing this at home. I followed these instructions to a T, and still somehow managed to have the screen not be able to turn on after the hard drive replacement. Then, once you’ve opened your Mac yourself, Apple will refuse to fix anything on the computer, and even other third party, Apple-authorized repair facility will refuse to repair it for you, and you will have to locate a non-authorized Apple repair facility. There, I am having to pay ~$600 to fix things that got screwed up, even though I followed the instructions here to a T, step by step, and did everything slowly and methodically.

Beware, if you’ve never done this before, that be locked out of ever being able to use an Apple repair facility, or Apple-authorized repair facility, if you mess things up here now.

The display cable, the wider one, has a lock on it , usually a plastic tape lift tab to release it, once thats flipped it should come out fairly easily, if your experiencing resistance and the cable isn’t coming out then check for this lock/latch, the power cable just pulls out, just don’t rush it everything should go fine, fairly easy to do with the end result a working iMac

Is it possible to replace the power cable if its damaged? I can’t seem to find anything about this.

After finishing my hard drive replacement I reconnected these connectors to test my display before using new adhesive. Everything was working beautifully. But then when I applied the new adhesive and went to seal the display on for good - the display power cable somehow became disconnected! I had to reopen the Mac for a second time which was far more difficult with new adhesive. When reinstalling double and triple check that the cables are securely inserted before the final seal. Sounds obvious but it’s quite the annoyance if something goes wrong at this point.

Very difficult to work with these connectors.

Power cable very difficult to unplug - data cable veeeeery difficult to plug in.

I noticed that working with the iMac positioned vertically (and with a proper support for inclination) makes this step slightly easier…

Interesting comments.. personally, I didn’t find the cables particularly difficult to detach and reattach. You do have to be patient and gentle. Personally, I found that a rolled up beach towel gently wedged between the unit and back of the display helped keep the glass up. Also, a small flashlight can be helpful to see the cables and connectors if you’re lighting isn’t perfect.

I’d agree to John - not overly difficult. My workaround was to prep the screen for re-installation and then place it in front of the standing machine. The cables are long and flexible enough to be put in place even in this state. You can easily attach the cables and continue with fixing the screen to the housing.

I would not recommend doing this step as pictured. The cable you are removing has little tabs on the wide side that can be depressed inwards towards the center of the connector, releasing the cable. If you just grab the cable as pictured and yank it out, without depressing the side tabs, you are likely to damage something. Don’t pull on the wires, use your fingernails at the connector to squeeze the very small little tabs inward to release the cable from the connector.

At this step, if you mess up anything with these 2 cables, especially when plugging them back in, even if you think you’re following the instructions here to a T, then you’re screwed.

I would highly, highly, highly recommend AGAINST doing this at home. I followed these instructions to a T, and still somehow managed to have the screen not be able to turn on after the hard drive replacement. Then, once you’ve opened your Mac yourself, Apple will refuse to fix anything on the computer, and even other third party, Apple-authorized repair facility will refuse to repair it for you, and you will have to locate a non-authorized Apple repair facility. There, I am having to pay ~$600 to fix things that got screwed up, even though I followed the instructions here to a T, step by step, and did everything slowly and methodically.

Beware, if you’ve never done this before, that be locked out of ever being able to use an Apple repair facility, or Apple-authorized repair facility, if you mess things up here now.

Can anybody upload an image of how the display can get damaged from removing it? I find it hard to believe (though I’m reading the horror stories here) that a whole display can get damaged. Especially when many of us were following to a T and being VERY CAREFUL.

Thanks.

First: During reassembly, I highly recommend you connect these cables and do a test boot BEFORE you remove the protective tape on the adhesive strips. That way you can fix any issues(like a damaged cable) if something is not right and you have not re-glued the screen back down which will cause a problem. If you have a second person and everything is working after test boot, you can just leave the cables connected, lift the bottom of the screen and have 2nd person pull the protective tape on the adhesive strips and you can set the screen in place. Second I damaged the video data cable during reassembly on my late 2015 iMac- I did not get the connector straight and I damaged the wires on the cable. I recommend you have someone else hold the screen while you attach the cables - they are fragile. Luckily, the data cable was easily replaced for only about $20. If you must do this by yourself, just be careful I highly recommend have 2 people at this step during reassembly.

At least on my “late 2013” model, the smaller display cable connector has tiny, tiny clips on the outside edges. These must be squeezed to unlatch it. Don't pull on the cable itself or the wires can be pulled out. Even with my small fingers, it was hard to grip the clips. When reconnecting, the connector will lightly snap into place.

I managed this step without any problems, but I had my wife hold the screen up while I disconnected/connected the cables. I STRONGLY encourage another pair of hands here so you can focus your full attention on being ultra careful with the cables.

On the 2015 there are 2 cables.

1. Once the display is loose use the Mac foam block sold from Ifixit to keep the display from rocking to hold open the glass

2. Blow out dust with canned air

3. Get a flash light and small flat edged screw driver

4. Use the screw driver to slow pry loose the connector from the socket by gently inserting it in the gap on the left and then on the right slowly easing the connector from the socket towards the top of the glass

5. The more center connector has a pull tape and a wire loop. Lift pull tape and the wire loop will raise up.

6. Pull the wire loop towards the top of the glass to slide out the connector from its socket

does anybody know how the Display Cabel pin assignment is? I want to try if I can attach the Panel to another grafic card

Thank you Stef, that's what i will do next time, i cracked the lower part of the screen went opening very slowly, that's probably why those "tabs are for !!

Thanks Stef, this has saved me! Simple yet very effective.

Yep, I cracked the lower corner of the display as well. I failed to work the adhesive enough to loosen it sufficiently. Be careful, I just had to buy my customer another screen!

There seems to be missing a step or two. As I was removing the old display, there are two wires that need to get transferred to the new replacement display. There is not note about these two wires located at the top of the display. The 1.128-inch ribbon cable and then this other 4-inch long, two-wire cable that goes to a very small circuit board that is 1/4 by 3/8 of an inch and seems to be adhered to the panel.I have not been able to get this cable off the old display. There is a port for it on the replacement display.

Note: When ordering this screen, and plastic cards as noted tools, ifixit.com did not list the pizza cutter or the new replacement adhesive strips. So now I’m not sure how to get the new one on and secure.

The adhesive strip along the bottom is designed with a pull tab on each outer end. Rather than lever and pull the screen simply carefully pull the tab which removes that half of the lower adhesive strip and frees up the screen.

Niemals den unteren Klebestreifen mit einem scharfen Gegenstand wie Rasierklinge oder so versuchen zu trennen, davon geht die Beschichtung des Displays kaputt und man hat hässliche Streifen unten hinter dem Glas. Stattdessen lieber versuchen, das Display nach oben zu klappen und abzuziehen.

translation from Bas Ti because this is very important:

Never try to separate the bottom adhesive strip with a sharp object such as a razor blade or something, the coating on the display will break and you will have ugly strips at the bottom behind the glass. Instead, try to flip up and pull off the display.

As mentioned before you can pull out the lower adhesive strip. Dont cut it or move the display up and down. This is even more dangerous. On the lower side of mac where the display glass ends is a offset. When moving the display up and down you might crack it over that offset.

Would have been helpful to box the same red area when using the plastic card to separate the glue. Since the red blocked picture is inverted, if someone doesn't pay close attention it may not be obvious that the area of concern is at the right top of the graphic pictures in which the plastic card use is being demonstrated..

you don't need to cut the bottom part as the bottom tape is stuck on each side and you can easily pull it out

What is the twisted wire taped to the back of the display that can bee seen in the upper right of the first two pictures? I have an 27” iMac without a screen an my replacement does not have this wire. I think it is a temperature sensor but do not know where it connects to.

Please update the picture to include the RED BOXED IN AREA that you refer to on all three pictures in this step. I have had a few zaps from these supplies and it is not pleasant.

J’ai réussi à intervenir dans l’iMac sans décoller l’ensemble de l’écran. Je l’ai ouvert en laissant la dernière partie collée (vers le logo Apple) et qui sert comme une charnière. Bien calé et assuré l’écran n’a pas bougé et j’ai pu changer mon disque dur facilement. Le grand avantage et d’avoir l’écran toute suite juste quand on le recolle par la suite.

Well, I of course touched a soldering point in the red area as my hand slipped. I heard and felt a tiny “click” and after replacing the HDD with SSD etc I can not power the iMac up anymore. Not a sign of life :-( I suppose I broke the power supply. Can someone confirm? Or could something else have broken too?

@john - there’s a slot on the back of the motherboard for a storage stick. fancy

You really should be using film handling or surgical type gloves to handle the screen to minimise finger grease on any of it. Even if it’s possible to clean most of it off, it can be corrosive over time.

hey Simon, I used 2-sided tape….this is assuming the new sensor doesn’t already come with an adhesive surface already applied.

a roll of kapton tape for your own peace of mind will make sure nothing detaches from thermally-induced adhesive crystallization

make sure you position it in such a way that you can easily plug the lead back into the mobo….not a lot of length to that wire

Howdy folks,

Thanks for all the tips, LCD sensor fitted and iMac back in action.

Never again!

Simon

Hello all. So I’m trying to pinpoint my backlight issue on my 2015 retina 5k - I noticed I’m missing my thermal sensor on the LCD. Would this help with the backlight? I’m sure it will keep my fans from going crazy. Any help would be appreciated! Note: I have LEDs except the 4th one. Thanks!

Be careful when removing the adhesive residue!

I didn’t know it, but I ended up leaving slight scratch marks that can be seen from the front side.

Incomplete guidance . Does not say how to transfer cables such as thermal sensor .

La traduction française est tronquée : “…plus faciles avec une cale de maintien pour iMac”

(https://eustore.ifixit.com/fr/Outils/Org...)

My $12.99 iMac Service Wedge looks like a $0 soft pillow from the guest room…

;-)

I didn’t unplug and de-route this cable. Later, Step 29, has you remove the left speaker. This isn’t necessary. If you can just move the speaker over to expose the hard drive mounting screws, so if you’re not going to remove the speaker, you don’t need to unplug it.

there is no need to disconnect the speaker, just unscrew it and move aside slightly to reach the HDD screws (about 5mm) - if you want to replace just the main HDD

If I leave my iMac unplugged for an extended period, say 24 or 48 hours, is it still possible to get an electric shock from the PSU? Do the capacitors eventually discharge?

make sure you’ve actually unplugged the mac when running this cable, and not had it plugged in to test the diagnostic LEDs, because one of those wee silver spots is carrying 230v, and its 6mm away from the place the cable runs, So if you have fat fingers like mine, that’s a free wake up zap

This is MUCH easier to do if the support bracket along the bottom is removed first. See Reemplazo de Placa Lógica del iMac Intel 21.5" Retina 4K Display (2017) step 25.

Use a P00.

To replace it, introduce it like in the photo at the link to be able to hold the right most holes of the chassis and bracket. Replace the first screw, align the bracket to the horizontal and add the screws from right to left. Each one will bring up the next hole in the bracket close enough to screw through. Reverse those directions if you are a leftie.

Pay attention: if pulling out the loudspeaker tear off the wire of the power button, Apple have not any service parts except for the whole rear housing!

This is MUCH easier to do if the support bracket along the bottom is removed first. See Reemplazo de Placa Lógica del iMac Intel 21.5" Retina 4K Display (2017) step 25.

Use a P00.

To replace it, introduce it like in the photo at the link to be able to hold the right most holes of the chassis and bracket. Replace the first screw, align the bracket to the horizontal and add the screws from right to left. Each one will bring up the next hole in the bracket close enough to screw through. Reverse those directions if you are a leftie.

It is difficult to remove the bottom of the speaker because it bends into the frame. Be careful to remove the power button cable, which also routes in a channel in the bottom of the speaker.

The trick with removing the left speaker is that you have to slide it up toward the top of the iMac (continuing to de-route the power button cable carefully as you go) to get it out from under the chin before you lift it up to remove it.

Is the WD hard drive an Apple Special with some internal rom or other thing? Planning to put in a Seagate Firecuda 2TB. Is there some special plug or temperature sensor requirement? Seems like there is only the SATA connector. Will I encounter fast fans? (can load the software to stop that). Think it’s a swap and is “easy”.

If you have the iMac sitting upright, there is a potential risk of dropping the screws into the iMac casing. Be cautious or lay it down flat.

Been there done that. Had to flip it and shake the heck out of it to get that srew to fall out!

Left hard drive bracket screws are T8!! Had to remove HD first before derouting left speaker cable.

Thank you iFixit for sending a T10 with magnetic tip. You saved me!

The bracket screws are T10. The screws on the left side of the SILVER hard drive itself, are T8. If you seem to need a T8, you are actually trying to remove the wrong two screws. Look immediately to the left of the hard drive & you will see the BLACK bracket frame with two screws that use T10.

mine were T8s

Bracket to iMac case screws,T8.

Which is fine.

Just as in the next step, T8 or T10.

Full removal of the speaker is unnecessary - just very carefully unplug the two-conductor power button cable, which is routed through the groove along the edge of the speaker enclosure. Next, unfasten the two large torx screws holding the speaker enclosure to the chassis. Now you can easily scoot the speaker away from the drive mount - move it over just enough to reach the drive mount’s 2 torx fasteners beneath the edge of the speaker (a CM or two). There’s now enough room to easily remove and replace the drive assembly .

Just wondering if the HDD 3.5 (3TB) in my 2015 27’ 5K iMac case are the ones with the temp control firmware onboard. Just got quote from Auhorised repair centre for 2x the normal price of a 3TB drive. They say I can drop in one i source myself if I like but I don’t want to get it back and have the fans run all the time. Thanks in advance :)

This step is unnecessary. Just leave the bracket in place and set the assembly aside.

On Late 2015 27” iMac I found that after removing this speaker, and the Right side one, I could reach under the motherboard and squeeze and disconnect the SATA data connector with a needle-nose and then remove the SATA power connector and slide the cable out from under the logic board without removing the board. The new cable slid in from the hard drive side with little effort.

If switching to an SSD, the posts on the drive can be removed and used on the 2.5” to 3.5” adapter tray.

In my case these were T9 screw posts. Late 2012 iMac. They had traces of Loctite on them.

Ich denke die Frontplatte hätte anschliessend auch wieder eingesetzt gehört - bin die Anleitung Schritt für Schritt durch gegangen, und mir ist leider gar nicht aufgefallen, dass dieser Schritt fehlt. Nun ist der iMac bereits wieder verklebt und beim Aufräumen ist mir die übrig gebliebene Frontplatte untergekommen.

Aber halb so schlimm, die SSD ist angeschraubt, kann sich also eh nicht bewegen.

My enclosure doesn’t look like this. All I received was a black back plate. Where is the rest of it? Oh boy

My iMac (27-inch, Late 2013) (Model Identifier: iMac14,2) (EMC: 2639), had a Seagate Barracuda 1.0TB HDD installed. There was no temperature sensor on the HDD. I have the Fan Controller that is pictured in this manual on Steps 39, 40 and 41. The photos do not show a small two-conductor cable connected from the Fan Controller circuit board to the logic board. There is usually a cable that connects the small circuit board, where the drive’s temperature is measured, to a connector on the logic board, but not in this iMac. For now, I have installed the Samsung 860 EVO 500GB SSD without a fan controller and it has been running for over two hours without a hint of the fan ramping up. Should I still install the Fan Controller and not worry about connecting the controller sensor to the logic board? Thank you for creating an excellent manual!

I just did this procedure with an A1419 (EMC # 2806) and didn’t buy the temperature sensor. I didn’t experience any loud fans afterwards. The machine was originally ordered with 3TB Fusion Drive. After installing the new 2TB SSD (WD Blue WDS200T2B0A) the Disk Utility showed an original 128GB PCI drive in addition to the new SSD. I ignored this PCI SSD and reinstalled OS X on the SATA SSD. All is good here! Oh, also I didn’t use any fancy 3.5” to 2.5” drive adapter, but a simple 3-dollar eBay adapter (can be found with this title, “2.5" to 3.5" Bay SSD Metal Hard Drive HDD Mounting Bracket Adapter”). I keep these laying around just in case. I did have to re-thread the screw holes to re-use the iMac’s HDD screw-posts (used tap & drill set, size 6-32 NC).

I just upgraded my late 2015 iMac with a 1TB Samsung 860 EVO and did not use a sensor. No fan or heat issues over the last week of use. Please note this Samsung drive is not the primary workhorse on the machine as I also upgraded my PCI ssd and use that as the primary drive. I have read on other sites that this model iMac does not need the sensor but I am not 100% on that.

une fois la sonde collé sur le ssd ou est ce que celle ci ce branche ? sur la carte mere ?

This was an understatement for my drive adapter. The adapter had threads that I believe were M3 threaded whereas the mounting pins are what I believer are 6-32 screws. The mounting pins are not threaded well for self-tapping, so I recommend finding an old screw that used to be used for mounting optical drives into PC cases and using those to thread the holes. You can make sure you have the correct size by screwing the sacrificial screws into the old hard drive where they should fit easily before using them to cut new threads into your 2.5” drive adapter. After that, the mounting pins went into the adapter with very little effort.

Ensure the glass lines up with the edge of the iMac

After replacing the adhesive strips with new ones and the screen connectors have been reconnected, place the lower edge of the screen on the bottom shelf” to take the weight, but don’t press it back in the shelf too much.

At this point if you’re careful you still have the ability to ensure the edges of the glass line up with the aluminium edges. As soon as the adhesive strips make contact with the glass you will quickly lose the ability to adjust this to line up.

What position should the iMac be in before doing this final comment related to setting the display on the “shelf”?