Sostituzione alimentatore iMac 27" 2017

What’s the point of this? You run the wheel around the outside, and then you lay it down anyway to pull the glass and do the rest. The wedge is not needed.

I have a story to tell about this teardown. It all went wonderfully well until after I completed the process and attempted to format my new SSD drive only to discovery that the capacity of the drive was 256GB… not the 2TB I was sure I had ordered. iFixit was very supportive and helpful in sending me a new set of sticky tape strips and and RMA to return the SSD and some of the other parts.

I finally had received my new set of strips and the 2TB SSD…. I figured, piece of cake… I already know how to do this… but I watched the video again and started following the teardown…

…apparently the new sticky tape strips was way more powerful that the original tape and while using the pizza cutter tool and not advancing much, I proceeded to use one of the iFixit credit card style wedges…. I now have 2 pretty severe cracks on the glass of my display, which as clearly explained by @mayer can only be replaced by an entire display… which runs at about $500. Cosmetically it looks horrible, but it works… for now.

Should you run a hair dryer along the edges first?

Der Stecker muss seitlich wie die meisten anderen Stecker in diesem Modell komprimiert werden, um ihn aus der Buchse auf dem Logicboard zu ziehen. Die Zugrichtung ist parallel zum Logicboard in Richtung Oberkante des iMac. Ziehen ohne seitliches Zusammendrücken der Backen am Stecker könnte den Stecker oder die Buchse beschädigen.

These instructions are unclear. They imply the cable can just be pulled out but this step had me stuck for a bit. Searching the webs, I discovered that there are little tabs on either side of the connector. I used my prod tool and poked one side and the connector came out a little. I poked the other side the connector came out without a fight.

The instruction for this step state this but I was still not expecting two cables. Finally figured out there is a Display Power and a separate Display Data cable.

After rocking the display back and forth a bit, I found it helpful to use my iMac opening tool to gently slide ever so slightly underneath the bottom of the glass to cut the adhesive. This was with the display lowered back into it its normal position. I just worked about 1 millimetre deep at a time and eventually cut through the ~8” adhesive strip at the bottom centre.

It's possible to skip this step and go to step 24, leaving the display attached. You'll want to open the display just enough to replace the drive, with the machine upright and supported so the display doesn't swivel (I fold up a small pillow and wedge it in there). This way you don't have to worry about damaging the display when removing it, or aligning it when replacing it (which can be difficult to do solo as it's big and heavy).

Using a T8 with a short handle is helpful here, and make sure it's well magnetized so you don't drop the screws for the hard drive (just leave the other ones in the speakers).

These are new steps from when I did this on my late 2015 retina iMac so I believe step 25 and 26 are optional (you can cope without doing it).

I did not find it necessary to remove these screws and this bar

I lost these 8 during the reassemble. The manual tells I need eight 3.2mm screws.

Can anyone help to clarify what screws I need. I don't really understand this size. Is this M2x3mm?

No comments on this ?

It's quite possibly the most difficult part to put back in the entire process

The screws are tiny and the there is no easy way to line up the holes on the bracket with the screws

Having got this far - it wasn't even all that necessary to remove this part in the first place

Severe pain in the neck

After an hour of painstaking mess - I managed to get 7 out of the 9 back in

By that time I could care less about the remaining 2

With the right tools and technique, the bracket can easily be replaced in under a couple of minutes.

Use a screwdriver with a magnetized tip which frees up one hand and place a screw on the tip first.

Then line up the screw hole on just one end of the bracket and using a pair of tweezers from the side, hold the bracket in place while you put in the screw.

Next, do the same on the other end of the bracket. After that, all of the screws in the middle are quick to replace. I didn't really have to touch the bracket again after the end screws were in place.

Hope that helps someone else since removing this bracket does make later steps a bit easier.

I found i didn’t need to remove the speaker nor the hard drive. In fact I managed to remove the old PSU without even removing the chin strap. However, to install the replacement PSU, I had to remove the chin strap. So I would say, remove the chin strap, but you can optionally leave the speaker and hard drive in.

While you do not need to fully remove the screws as once you loosen them a few turns the speaker becomes free. I found that after the removal of the speaker, I turned it over and popped the screws out as this made it easier to replace it later as I could see the alignment before putting the screws back in. If not you may be off a little and you do not want to force the screw back in.

I used a pill container that I got from Walgreens to hold all of the fasteners I removed during the disassembly process. The container has 14 compartments (individual compartments for each morning and evening of the week). I put a small piece of paper in the compartment with the fasteners to note the name and step of the procedure and the size of the tool I used. Hopefully this will be useful when I go to put it back together again.

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.

on the 2019 iMac, it is horizontal not vertical so pull it horizontally out.

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

This is MUCH easier to do if the support bracket along the bottom is removed first. See Sostituzione scheda logica iMac Intel 21.5" Display Retina 4K (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 Sostituzione scheda logica iMac Intel 21.5" Display Retina 4K (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.

I found this cable very difficult to disconnect, be very careful because the cable is between a black tape and it's stuck very hard to the logic board and the cable is very short and you don't have space to move and separate it from the connection! Be patient and take the time you need

I found than putting the flat end of the spudger at the center of the cable, and tilting it got the cable out without an issue.

I was able to use the flat end of the spudger on the sides. You can see a tiny little clip on each side. Be very gentle!

This is MUCH easier to do if the support bracket along the bottom is removed first. See Sostituzione scheda logica iMac Intel 21.5" Display Retina 4K (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.

The top right screw on the power supply actually screws into a stand-off screw connected to the back of the iMac case. Once you have removed the 4 x Torx 8 or 10 screws you can move the power supply enough to see the upper face of it.

It has a Torx 25 slot in it and comes out easily. This will give you a lot more room for your fingers in Step 40, depressing the tab on the DC power cable connector to pull it out, and when replacing it on reassembly. You may find it won’t require you removing the support bracket as in the suggestion above.

Remember to push in the disconnect tab on the large connector. Carefully insert your finger and push on the tab before you pull on the connector.

Thank you Manuel, this was a tricky one.

Yes, I pulled the whole socket out because I didn’t know about the tab. Fortunately I was able to place it back in. Not sure if it was glued or how it was anchored but it seems to have a solid connection and I can’t easily pull it out by hand. Once I plug the power cable back in should be ok.

To reassemble, do the same in reverse but keep power supply board more upright than slanted down when re-inserting it in to the lower right corner. The lower right screw post has an protrusion under/behind it and the Power Supply's small 2 wire plug must fit between the front of your Mac and the obstruction. Then it just slides right in and then screw it down.

There is a small release tab on the cable.

Wear gloves when doing this to reduce any shock. The size of those capacitors are very unnerving and scary. Also those solder joints.