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Introducción

Use this guide to replace a faulty power supply in your iMac Intel 27" Retina 5K Display.

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.

    • With the hinge free to move, the iMac will be unbalanced and hard to work on. Repairs can be completed with the iMac laying down, but are faster and easier with an iMac service wedge.

    • If you are using the iFixit cardboard service wedge, follow these assembly directions to put it together.

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    • 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 case.

    • 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" (9.5 mm) into the display. You risk severing antenna cables and causing serious damage.

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    • 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.

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    • Continue wheeling the tool up around the top left corner.

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    • Cut the adhesive along the top left of the display.

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    • 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.

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

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

  8. iMac Intel 27" Retina 5K Display Power Supply Replacement: paso 9, imagen 1 de 2 iMac Intel 27" Retina 5K Display Power Supply Replacement: paso 9, imagen 2 de 2
    • 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.

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    • While the opening tool did the lion's share of the work, 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, insert a plastic card between the display and frame.

    • Be careful not to insert it more than 3/8" (9.5 mm), or you may damage internal components.

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    • Gently twist the plastic card to open the space between the display and frame, and cut any remaining adhesive near the corner.

    • Using too much force will crack the glass. Work carefully, and don't try to create a gap any larger than about 1/4" (6 mm).

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    • Be sure to stop cutting before the iSight camera in this step, or you may damage it.

    • Slide the card toward the center of the display, to cut any remaining adhesive.

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    • Put the card into the corner again and let it stay there to keep the adhesive from resettling.

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    • Insert a second card into the gap between the display and frame in the top left corner.

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    • Gently twist the card, slightly increasing the space between the display and frame.

    • As with the other side, move slowly to allow the adhesive to break, and be careful not to over-stress the display glass.

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

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    • Insert the card back into the top left corner.

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    • Only lift the display a few inches—it is still attached to the iMac by data and power cables.

    • With the cards inserted as shown near the corners, gently twist the cards 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 adhesive in the problem area.

    • Begin to lift the top of the display up from the frame.

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    • While holding the display up with one hand, use the other to unplug the display power cable.

    • Lift the display up enough to have easy access to the connections, but not so much that you stretch the cables and stress their connections (about 8").

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    • Flip up the metal retaining bracket on the display data cable.

    • Disconnect the display data cable.

    • This is a delicate connection that can easily be broken. Be sure to pull the display data cable connector straight out of its socket, toward the top of the iMac.

  20. iMac Intel 27" Retina 5K Display Power Supply Replacement: paso 21, imagen 1 de 2 iMac Intel 27" Retina 5K Display Power Supply Replacement: paso 21, imagen 2 de 2
    • 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.

    • Remove as much of the adhesive as possible by grabbing it at the outer edges, and then pulling or rolling it towards the middle.

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    • Be very careful not to touch the capacitor leads or any exposed solder joints on the back of the power supply (boxed in red).

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

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    • Be very careful handling the display—it's big, heavy, and made of glass. The display has fragile edges. Avoid lifting the display by the corners.

    • Lift the display up from the frame and remove it from the iMac. Lay the display face down on a flat, soft surface.

    • It may be necessary to slowly lift from one side, to peel against the remaining adhesive.

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

  23. iMac Intel 27" Retina 5K Display Power Supply Replacement: paso 24, imagen 1 de 1
    • If you are replacing the display panel, you may need to transfer additional components from the old panel to the new one. Compare the back of the old display with the replacement display. Note all cables, sensors, and foam cushioning that are missing from the new display.

    • If there is a wire or cable underneath adhesive tape, always pull the tape off first.

    • If the cable is glued to the chassis, use a heated iOpener or a hair dryer to soften the adhesive first. You can then slide an opening pick underneath the cable to loosen it. Never pull directly on the delicate connectors.

    • Slide an opening pick underneath the foam cushion pieces to separate them from the display, and gently pull them off. You may need some double sided tape to re-attach them to the new display.

  24. iMac Intel 27" Retina 5K Display Power Supply Replacement, Remove the support bracket: paso 25, imagen 1 de 2 iMac Intel 27" Retina 5K Display Power Supply Replacement, Remove the support bracket: paso 25, imagen 2 de 2
    • Use a Phillips screwdriver to remove the nine 3.2 mm screws securing the support bracket.

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

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

  26. iMac Intel 27" Retina 5K Display Power Supply Replacement, Remove the left speaker: paso 27, imagen 1 de 1
    • Remove two 10 mm T10 screws.

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    • Unplug the left speaker cable by pulling it straight up out of its socket on the logic board.

    • De-route the cable from the gap between the hard drive and logic board.

    • If the gap between the hard drive and logic board is too narrow for the speaker cable, disconnect it and leave the cable in place.

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    • Be careful not to touch any solder joints on the back of the power supply. Capacitors may be charged enough to give you a dangerous shock.

    • Use a spudger to disconnect the power button connector from its socket on the logic board.

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    • Lift the left speaker straight up, until the power button cable is exposed (about 0.5 inches).

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    • Gently de-route the power button cable from its groove in the left speaker.

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    • Lift the left speaker straight up and remove it from the iMac.

    • If the gap between the hard drive and logic board was too narrow to free the speaker cable earlier, gently pull it free as you remove the speaker.

    • Push from the connector end as you pull from the speaker end to thread the cable under the hard drive's right bracket.

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    • Pull straight up on the SATA data/power cable to disconnect it from the drive.

  33. iMac Intel 27" Retina 5K Display Power Supply Replacement: paso 34, imagen 1 de 1
    • Remove two 7.3 mm T10 screws securing the left hard drive bracket to the rear case.

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    • Grab the hard drive and left hard drive bracket together.

    • Tilt the left side up away from the rear case, and slide the assembly to the left.

    • Remove the hard drive and left hard drive bracket from the iMac.

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    • Remove the left hard drive bracket.

  36. iMac Intel 27" Retina 5K Display Power Supply Replacement, Remove the power supply: paso 37, imagen 1 de 2 iMac Intel 27" Retina 5K Display Power Supply Replacement, Remove the power supply: paso 37, imagen 2 de 2
    • 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.

    • Disconnect the power supply control cable from the power supply.

  37. iMac Intel 27" Retina 5K Display Power Supply Replacement: paso 38, imagen 1 de 1
    • Remove the following four screws securing the power supply to the rear case (size T8 or T10 depending on the exact model):

    • Two 23.7 mm Torx screws

    • Two 7.3 mm Torx screws

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    • Do not attempt to remove the power supply from the case; it is still attached to the logic board by two cables.

    • Move the power supply board towards the left edge of the case and up to free it from the notch in the logic board.

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    • Depress the tab on the DC power cable connector, then pull it straight out of its socket on the back of the logic board.

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    • 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 top of the power supply towards you, like opening a mailbox, to reveal the AC inlet cable connector.

    • Disconnect the AC inlet cable connector.

Conclusión

To reassemble your device, follow these instructions in reverse and use our Adhesive Strips Guide to reattach the display glass.

Take your e-waste to an R2 or e-Stewards certified recycler.

Repair didn’t go as planned? Try some basic troubleshooting, or ask our Answers community for help.

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8 comentarios

I changed the power supply and that didn't fix the issue. Imac still won't power on and I'm only one of the LED lights on the logic board light up. Bad logic board?

Rose Yellen - Contestar

I have the same issue. Lowest LED of the four lights up green, but no chime, nothing. Did you ever find a fix?

Ivan - Contestar

Great guide. But how does one test said power supply to compare broken vs new?

Armand Viaud - Contestar

Same question, have replaced power supply still bottom led is the only lit led. It blinks once when power button pressed. no other lights come on

Jason Jenkins - Contestar

Last comment only have the last led On , same problem any solution ?

Johnny - Contestar

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