iMac Intel 21.5" Retina 4K Display 2019 Power Supply Replacement

Written By: Adam O'Camb

Comments: 30

iMac Intel 21.5" Retina 4K Display 2019 Power Supply Replacement

Difficulty

Moderate

Steps

Time Required

40 minutes - 1 hour

Introduction

Use this guide to replace the power supply in your 21.5" Retina 4K Display 2019 iMac.

Some images in this guide use an older iMac, which has minor visual differences. These differences do not affect the repair procedure.

This guide 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.

Tools

Parts

Step 1

With the hinge free to move, the iMac will be unbalanced and hard to work on. Place an iMac service wedge, in the stand to stabilize the iMac.
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.

Maybe your directions should suggest fixers to buy RAM cards in pairs. I wanted 32 Gig of RAM, and I bought and installed one 32 G RAM and while it seems fine, one source told me it would be 5-10% faster if I had put in two 16 RAM cards. Is that accurate?

BRUCE CLARKE - 26/10/20

it would at least be that much faster, in theory some applications should run twice as fast

blakebest -

Step 2

Starting on the left side 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.

Step 3

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

Step 4

Continue running the tool up around the top left corner.

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 a few times to ensure you completely cut through the adhesive.

Step 7

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

Step 8

Push 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.

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.

9.5mm in the rest of the world

Tal Glazer - 22/01/21

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".

Which is around 6.5mm

Tal Glazer - 22/01/21

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.

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.
Stop sliding just before the iSight camera to avoid damaging the 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.

Ich habe den unteren Klebestreifen gar nicht gelöst! --> Monitor (Glasscheibe) nach vorne auf ein dickes Kissen gelegt - so dass das Glas nur ca. 80° Winkel nach vorne zu liegen kommt und dann habe ich die Festplatte getauscht! So konnte ich die untere Klebeleiste wieder verwenden und hatte genügend Platz um die senkrechten und oberen Leisten zu verkleben!
Tip: Klebestreifen zuerst auf dem Alugehäuse befestigen......

Fridtjof Schüssler -

Step 19

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").
Hold the display with one hand while using your other hand to unplug the display power cable.

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.

delacrj2 - 22/12/17

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.

delacrj2 - 22/12/17

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.

Jeremy Brainard - 19/04/19

This step should be done with extreme caution and care, as this step 19 is not described in great detail (sorry, author).

The first (most outward) cable will slide out by gently pulling it by its tabs. The second (inner) cable is more tricky, as the locking lever must be moved backward first, before gently pulling backward on the cable connector. The angled tweezers are useful here, to help lift that locking lever, because fingers are too big for this.

Ernst -

be VERY careful and SLOW...take your time. These displays crack VERY easily when removing and they'll spider web on you. I've done probably 20 or so of these and cracked 3 being super careful.....ugh.

Faslane -

I found the best way to unplug this display power cable was to use my right hand, and the fingernails of my index finger and thumb to grab the ends of the tabs on either side of the connector, squeeze, and pull the connector out gently.

Phil McInnis -

i think the cable nearest the case edge is held in by friction and can be gently pulled, maybe with fingernails or a spudger. The next cable is held by a wire lever clip as described above it unlocks so the cable can be removed. These cables are also fiddly to re-insert, I didn't get one of them home and had no display after power-up, so at the end, don't re-seal the screen until tested.

Peter Taffs -

Step 20

Continuing to support the display with one hand, 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, keeping it parallel to the motherboard, to avoid damaging it.

Cannot seem to find a replacement cable for this, as I suspect mine is damaged. Can’t even find a part number. Anyone know what it might be?

Jeremy Brainard - 19/04/19

https://www.amazon.com/gp/product/B08TTL...

That's the part I ordered for mine and it seems to work ok. I did make a point of contacting the seller and advising them of my requirement and they ensured I got the right part and it matches the description of the link. Bear in mind I bear no responsibility if yours does not work since I am just sharing what I did and what I ordered. Thanks.

Jim Stanford -

I also need that cable.

cameronjpu - 24/03/20

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.

Jim Stanford - 09/05/22

For this particular cable, take a good look before pulling on anything. Plug is locked on its socket with a bracket. You can lift this bracket by holding the small, flat black plastic handle that is attached to it. If you're struggling to grab it, use the end of the pizza roller handle to lift it, or the tweezers. Cable then comes off by pulling parallel to the main board.

Froggy Manny -

How can I tell if either of this cable is bad? My iMac display won't turn on after reconnecting it. I'm using an external display and everything is working except for the iMac display. If I go to settings - display the built-in display is recognize. But again nothing shows up in the screen - not even the apple logo when turning it on.

Carlos Sosa -

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.

I was fretting that i would break my screen, it's really hard to see what is holding the screen in place and i was ready for it to snap the last 1/2 inch or 12mm of the glass I worked slowly and as you say, keep lifting and working it gently until you can see and cut the remaining adhesive.

Peter Taffs -

Step 22

If necessary, a plastic card can be used to cut any remaining sections of the bottom adhesive strip.

The bottom adhesive strips have small tags at a 90 degree angle that can be used as handles to strip them out at this point. https://d3nevzfk7ii3be.cloudfront.net/ig...

Dom - 05/09/20

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.
After the adhesive is cut, it cannot be used to re-seal the display in place. Follow this guide to replace the adhesive strips that secure the display to the rear enclosure.

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
You may need to peel up the display adhesive lining the bottom edge of the iMac enclosure to access the screws.

These screws are VERY small and very easy to lose. Ideally you use a magnetized screw driver to help here.

Charlie Nancarrow -

Step 25

Remove the lower support bracket (a.k.a. "chin strap") from the iMac enclosure.

The 'chin strap' is very easily bent, which makes it difficult to put the very small screws back in place.

Charlie Nancarrow -

Questa staffa a cosa serve ?

Nicola Demetrio -

Non rimetterlo che cosa comporta?

Nicola Demetrio -

Step 26

Remove the following T10 Torx screws securing the hard drive brackets to the iMac:
Two 21 mm screws
One 9 mm screw
One 27 mm screw

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 (%#*@).

roberttrevellyan - 19/09/17

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

anonymous 523 - 19/10/20

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

Charlie - 05/02/21

buongiorno, l'imac del 2019, non monta alcuna ssd, ma monta una m2 direttamente sulla scheda madre!

pertanto nella guida andrebbe aggiunto il cavo sata con sensore temperatura da aggiungere sulla scheda madre, per poter collegare un nuovo hd ssd altrimenti rimarrete come me bloccati con un imac aperto e non assemblato, in attesa di ricevere il cavo acquistato su internet da amazon o terze parti.

vi consiglio inoltre di aggiungere una foto reale del ò'imac 2019 nella guida in cui manca l'ssd, renderà subito la problematica che avranno in molti!

Donato Altomare -

Hi, mine doesn’t HAVE an HD/SSD to remove, the bay is empty (yes it was fully working yesterday. So what do we do ? I see someone else with the sane issue above….

Jeroen Speak -

Step 27

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

Step 28

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.

Step 29

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 30

Remove the two 7.2 mm T8 Torx screws securing the power supply to the rear enclosure.

Step 31

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.

Step 32

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.

Step 33

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

Step 34

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 35

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.
Do not let any of the exposed solder joints come in contact with a metal surface, as that can cause a short.
Flip the power supply over to access the DC power cable connection behind the logic board.
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.

Step 36

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 release 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 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)

Fettler -

Step 37

Remove the power supply from the iMac.

Conclusion

Compare your new replacement part to the original part—you may need to transfer remaining components or remove adhesive backings from the new part before installing.
To reassemble your device, follow the above steps in reverse order.
Take your e-waste to an R2 or e-Stewards certified recycler.
Repair didn’t go as planned? Check out our Answers community for troubleshooting help.

Author

Adam O'Camb

Member since: 11/04/15

195421 Reputation

iMac Intel 21.5" Retina 4K Display 2019 Power Supply Replacement

Introduction

Tools

Parts

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