iMac Intel 20" EMC 2105 and 2118 Power Supply Replacement

Keep those electrons flowing by replacing your broken power supply!

Image #1

Edit Step 1 Access Door  ¶ 

  • Loosen the two Phillips screws securing the access door to your iMac.

  • Both screws remain captive within the access door.

  • Remove the access door.

  • Before beginning the repair, unplug the computer and press and hold the power switch for 20-30 seconds, to discharge internal capacitors.

Image #1

Edit Step 2 Front Bezel  ¶ 

  • Remove the following screws along the lower edge of your iMac:

    • Three 6 mm T8 Torx screws

    • One 8 mm T8 Torx screw (Right side of the RAM slot on 2105)

Image #1

Edit Step 3  ¶ 

  • Re-orient your iMac so it sits upright on the stand.

  • Insert a plastic card up into the corner of the air vent slot near the top of the rear case.

  • Push the card toward the top of the iMac to release the front bezel latch.

  • Pull the front bezel away from the rear case.

  • Repeat this process for the other side of the front bezel.

  • It may be necessary to apply several layers of duct tape to the top of the access card to aid in releasing the latches. Or use two cards for the additional thickness.

  • If the bezel refuses to release, try lifting the lower edge of the front bezel slightly away from the rear case (detailed in the next few steps) and repeat the latch release process.

Image #1

Edit Step 4  ¶ 

  • Lay your iMac stand-side down on a flat surface.

  • To lift the front bezel off the iMac, simultaneously:

    • Use your thumbs to press in the RAM arms and hold the iMac down.

    • Use your index fingers to pull the small bridge of material on the front bezel toward yourself.

    • Pull the front bezel up with your index fingers.

  • Once the small bridge of material has cleared the RAM arms, lift the front bezel by its lower edge just enough to clear the bottom edge of the rear case.

Image #1

Edit Step 5  ¶ 

  • Lift the front bezel off the rear case and rotate it away from the bottom edge of the iMac, minding the camera and microphone cables still attached to its upper edge.

Image #1

Edit Step 6  ¶ 

  • If necessary, remove the strip of tape covering the microphone cable connector.

  • The microphone connector is located near the inside of top edge of your iMac.

Image #1

Edit Step 7  ¶ 

  • Disconnect the microphone cable.

  • Disconnect the camera cable by pulling its connector away from the socket on the camera board.

  • The camera cable connector and socket are delicate and easily bent. Remove with caution.

Image #1

Edit Step 8 Lower EMI Shield  ¶ 

  • Peel up the lower EMI shield from the rear case.

  • It is only necessary to peel the shield up from three sides. Leave it attached to the display.

  • If you happen to rip the EMI shield, use a piece of foil tape to cover the tear.

Image #1

Edit Step 9  ¶ 

  • Tape the EMI shield to the face of the display to keep it out of the way.

Image #1

Edit Step 10 Display  ¶ 

  • Remove the two 5 mm T6 Torx screws securing the display data cable connector to the logic board.

  • Pull the display data cable connector up off the logic board by its black pull tab.

Image #1

Edit Step 11  ¶ 

  • Peel back the EMI tape from the two vertical edges of the display.

  • During reassembly, it is helpful to use several small strips of tape to hold the EMI shielding along the left and right edges of the display footprint out of the way before lowering the display into the rear case of your iMac.

Image #1

Edit Step 12  ¶ 

  • Allow the lower EMI shield to hang down from the display.

  • Remove the four 7.5 mm T10 Torx screws securing the display to the rear case.

  • The screws are recessed, so a thin magnetic screwdriver aids in removal. Most bit drivers are too short to reach these screws.

Image #1

Edit Step 13  ¶ 

  • Lift the lower edge of the display and rotate it toward the top edge of your iMac.

  • Do not lift it too much, as the inverter cables are still attached.

Image #1

Edit Step 14  ¶ 

  • Disconnect both inverter cables from the inverter board.

  • These connectors are seated very tightly in their sockets. It is helpful to use your fingernails or the tip of a spudger to push the ears on either side of the connectors to dislodge them from their sockets. A small pair of hemostats helps a lot.

Image #1

Edit Step 15  ¶ 

  • Disconnect the two inverter cables at the top edge of the inverter using the method explained in the previous step.

Image #1

Edit Step 16  ¶ 

  • Rotate the display until it is nearly perpendicular to the rear case and lift it up to peel it off the EMI shield stuck to its top edge.

Image #1

Edit Step 17 Speakers  ¶ 

  • Remove the single T10 Torx screw securing the left speaker to the rear case.

  • Pull the left speaker out of the rear case.

  • The screw for the left speaker is longer than the screw for the right speaker.

Image #1

Edit Step 18  ¶ 

  • Use the flat end of a spudger to pry both antenna connectors up off the AirPort Extreme card.

    • Some models may have only one AirPort antenna wire.

Image #1

Edit Step 19  ¶ 

  • Use a metal spudger to disconnect the SATA data cable up off the logic board.

  • The SATA connector on most iMacs tends to stick in its socket on the logic board. If you are having trouble disconnecting the SATA cable, insert a metal spudger or any other thin tool into the gap between the SATA connector and its socket and twist the spudger's shaft to safely separate the two pieces.

Image #1

Edit Step 20  ¶ 

  • Pull the IR board cable connector away from its socket on the IR board.

  • Pull the connector parallel to the face of the logic board.

Image #1

Edit Step 21  ¶ 

  • De-route the speaker cables from beneath the IR Board and heatsink assembly.

Image #1

Edit Step 22  ¶ 

  • Remove the single T10 Torx screw securing the right speaker to the logic board.

  • Lift the right speaker out of the rear case and move it out of the way.

  • Both speakers are still attached to the logic board by the speaker cable.

Image #1

Edit Step 23  ¶ 

  • Disconnect the speaker cable connector by lifting it straight up off its socket on the logic board.

  • Pull the connector parallel to the face of the logic board.

Image #1

Edit Step 24 Logic Board  ¶ 

  • Disconnect the CPU fan and power button from the logic board by pulling their connectors straight up off the sockets on the logic board.

Image #1

Edit Step 25  ¶ 

  • If necessary, remove the pieces of tape holding the SATA data cable to the logic board.

  • Move the SATA data cable away from the face of the logic board.

Image #1

Edit Step 26  ¶ 

  • Disconnect the DC-In cable by simultaneously depressing both locking arms and pulling its connector away from the socket on the logic board toward the top of your iMac.

  • After both locking arms pass their retaining tabs, it is helpful to push the arms toward the top edge of your iMac while wiggling the connector.

Image #1

Edit Step 27  ¶ 

  • Pull the ambient light sensor cable connector up off the logic board.

Image #1

Edit Step 28  ¶ 

  • Use the flat end of a spudger to pry the Bluetooth antenna cable connector up off the Bluetooth board.

Image #1

Edit Step 29  ¶ 

  • Carefully de-route the IR board cable out from under the IR board and move it out of the way of the logic board.

Image #1

Edit Step 30  ¶ 

  • Disconnect the following connectors from the logic board:

    • Camera/IR board cable.

    • Optical drive fan.

  • When removing the optical drive fan connector, it is helpful to use a spudger or your fingernails to push the ears on either side of the connector toward the top edge of the iMac.

  • To aid in removing the camera/IR board connector, it is helpful to use one hand to pinch the cables against a spudger and pull up toward the top edge of the iMac while pulling up gently on the cables with your other hand.

Image #1

Edit Step 31  ¶ 

  • Disconnect the optical drive thermal sensor cable from the logic board by pulling its connector away from the socket on the logic board.

  • Pull the connector parallel to the face of the logic board.

Image #1

Edit Step 32  ¶ 

  • Remove the two T6 Torx screws securing the optical drive ribbon cable connector to the logic board.

Image #1

Edit Step 33  ¶ 

  • Use the flat end of a spudger to pry the optical drive ribbon cable connector up off the logic board.

  • The connector is most easily removed when prying from the top or bottom of the connector.

  • Bend the optical drive ribbon cable back away from the logic board.

  • Be very careful when moving the optical drive ribbon cable as it is delicate and easily ripped.

Image #1

Edit Step 34  ¶ 

  • Disconnect the following connectors from the logic board:

    • Hard drive thermal sensor cable.

    • CPU fan cable.

  • When removing these connectors, it is helpful to push the ears on either side of the connector with your fingernails or the tip of a spudger toward the top edge of the iMac.

Image #1

Edit Step 35  ¶ 

  • Remove the two T6 Torx screws securing the top of the heat sink framework to the chassis.

Image #1

Edit Step 36  ¶ 

  • Remove the following seven screws securing the logic board to the rear case:

    • Three coarse-thread T10 Torx.

    • Three fine-thread T10 Torx.

    • One long coarse-thread T10 Torx.

Image #1

Edit Step 37  ¶ 

  • Carefully rotate the top edge of the logic board out of the rear case and lift the board up out of the iMac, minding the RAM arms and any cables that may get caught.

  • Be especially careful with the hard drive thermal sensor cable that is routed underneath the heat sink framework.

  • Only handle the logic board by its edges.

Image #1

Edit Step 38 Power Supply  ¶ 

  • 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 to avoid a high voltage shock from the many large capacitors attached to the board.

  • If necessary, remove the tape covering the inverter cable.

Image #1

Edit Step 39  ¶ 

  • Disconnect the inverter cable by pulling the connector away from its socket.

Image #1

Edit Step 40  ¶ 

  • If necessary, remove the tape covering the metal chassis where the AC-In cable resides.

Image #1

Edit Step 41  ¶ 

  • Use a pair of tweezers to pull the AC-In cable out from underneath the chassis.

Image #1

Edit Step 42  ¶ 

  • Disconnect the AC-In cable by depressing the lock mechanism while pulling the connector away from its socket.

Image #1

Edit Step 43  ¶ 

  • Remove four T10 Torx screws securing the power supply to the rear case.

  • The fine-thread screw belongs in the lower right corner of the power supply. When reinstalling the power supply, install the fine-threaded screw first.

  • Lift the power supply out of the rear case, minding the AC-in cable that may get caught.

  • Do not touch the face of the power supply board to avoid electric shock.

To reassemble your device, follow these instructions in reverse order.

For more information, check out the iMac Intel 20" EMC 2105 and 2118 device page.

Required Tools

TR8 Torx Security Screwdriver

$5.95 · 50+ In stock

Spudger

$2.95 · 50+ In stock

T6 Torx Screwdriver

$5.95 · 50+ In stock

T6 Torx Screwdriver

$9.95 · 26 In stock

T6 Torx Screwdriver

$4.95 · 50+ In stock

Related Products

iMac G5/Intel Power Supply

$139.95 · 8 In stock

Recommended Tools

Universal Drive Adapter

$29.95 · 50+ In stock

iFixit Lock Pick Set

$29.95 · 50+ In stock

Inspection Scope

$39.95 · 50+ In stock

Frictionless Ratchet

$24.95 · 50+ In stock

Portable Anti-Static Mat

$34.95 · 39 In stock

Comments Comments are onturn off

Excellent guide !

geonosysinfo, · Reply

This guide was awesome. The iMac power supply replacement is a lot of work/steps but fixed an intermittent power supply problem for less than a $100 US dollars.

Pragmatic, · Reply

I have never seen a pict of the bezel latch, I hope this picture link helps you to figure out what is inside that you need the cc to hit to release, I had a tough time making it work but managed just before I gave up! http://i209.photobucket.com/albums/bb35/...

ReneBruce, · Reply

the photo of latch is no longer there at Photobucket

rmshreffler,

When you put this back together, make sure you place the bevel latches UNDER/INSIDE the case frame.

robino, · Reply

Quote from ReneBruce:

I have never seen a pict of the bezel latch, I hope this picture link helps you to figure out what is inside that you need the cc to hit to release, I had a tough time making it work but managed just before I gave up! http://i209.photobucket.com/albums/bb35/...

Thanks, your picture helped me.

robino, · Reply

Rather than through the vent at the back. Ease the bottom of the front bezel away from the screen and then in the gap created between the screen and the front bezel, insert your card here and push up to release the latch. This is especially the method to use, if you have already tried everything else above, as you may have bent the latches, and you'll never get them to relase the conventional way.

Charlie, · Reply

On the 24 inch model, there are no latches. Instead the front bezel has four tabs which slot into the rear case. It's very easy to remove.

manfred, · Reply

Wow, I really got stuck on the bezel. I tried a credit card, even a flexible metal scraper, nope nothing budged. I finally got going with help from this video: http://www.youtube.com/watch?v=QzuBW3mu7... which the guy has the machine lying on its back, then you can carefully bend the front bezel up until you see the latches, and I got the scraper in front of the screen and un-did the latches that way. Onto the next step!

sleestack, · Reply

Replaced one of the redundant images of the card going into the slot, with the previously linked image of the latch itself. I was struggling to figure out how to get the thing open, thinking it was a latch that pushed *up* to the top of the system, but it actually pushes *forward* towards the screen. That accounts for the bending of the card, and the excess length required to insert it. After figuring that out, the case came off nicely.

Matt Falcon, · Reply

Apple uses a powerful magnet to release these latches, but the official tool is not available. If you have access to a few failed hard drives, you can take out the magnets from those, and stack them up to have a magnet strong enough to easily open these latches.

Simply place the magnet on an upper corner of the machine, and when you hear a click, gently pull the corner of the front case forward. Repeat the process for the other upper corner. Use care not to pull on the iSight cables.

Note: Use care when handling the hard drive magnets, they are powerful, and you don't want them to snap together on your fingers. OUCH!

Zaphod, · Reply

This is definitely the hardest part of this repair. I ended up doing what Charlie did and got it off after a lot of frustration.

aseisman, · Reply

The iMacs I've taken apart open simply with a magnet. I made a video to show exactly how the latch works inside. You do need a strong magnet like the hard drive internal magnet suggestion however they can be found in many places, just look for 'rare earth' or 'neodymium' and you'll find one. probably .3" cube would be big enough.

http://youtu.be/yvq035edr-I

there is the video that shows how the latch works. of course you may need TWO magnets to do both latches at the same time.

awr, · Reply

i posted a note on the next page about disconnecting the microphone and camera cable. may help. reed it before disconnect.

sebalancea, · Reply

there's no need to disconnect the microphone and camera cable. you can work against a wall and carefully rest the frame and the display on the wall.

sebalancea, · Reply

Quote from sebalancea:

there's no need to disconnect the microphone and camera cable. you can work against a wall and carefully rest the frame and the display on the wall.

I didn't even use the wall, I just carefully pivoted the frame backwards and laid it on the table without disconnecting the wires

Bob, · Reply

Be careful. My microphone and camera cables looked a little bit different from this. My camera cable connector did NOT plug directly into the camera board (and I almost tried pulling the cable out of the board), but rather there was a cable to cable connector that was stuffed behind the monitor. I had to skip this step until the monitor was out. I have an early 2006 20" iMac.

avcaruso, · Reply

I didn't see the need to tape the foil to the display (and I didn't want to get any sticky residue on the screen), so I skipped this bit with no problems.

Bob, · Reply

Quote from Bob:

I didn't see the need to tape the foil to the display (and I didn't want to get any sticky residue on the screen), so I skipped this bit with no problems.

I agree, and tape doesn't stick to the screen (I tried and the tape came loose before I was done)

Wizbang FL, · Reply

This would be a really good time to change the PRAM battery. They only last 4-5 years, and cost very little. It'll save another teardown in the near future. (3v CR2032)

Bob, · Reply

Quote from Bob:

This would be a really good time to change the PRAM battery. They only last 4-5 years, and cost very little. It'll save another teardown in the near future. (3v CR2032)

Good idea, I just replaced this. $5 @ radioshack.

sleestack, · Reply

I found that disconnecting the display cable at the LCD end was easier. There are 2 v small clips either side of the ribbon cable, squeeze together and the cable disconnects from the panel.

KazR, · Reply

on this step I just forgot (there always something to forget!!) to connect back display data cable connector to the logic board, after I replaced the hard drive. Don't worry nothing happens. Hwen I switched on the iMac and it was just functioning alright and normal but I wasn't able see anything other than a black screen :)

If you got a black screen but a normal white light on the right bottom corner, think abot the connector !

joleisa, · Reply

This is tricky and took some time and patience. It is best to have some foil tape handy because the EMF shield tears easily. Likewise when reinstalling the screen and EMF shield, it helps to have a partner who can stop the foil to the side of the screen from getting folded under the screen when you lower it back into position, ready to tape it back onto the edge of the screen.

mindzeebeez, · Reply

Quote from mindzeebeez:

This is tricky and took some time and patience. It is best to have some foil tape handy because the EMF shield tears easily. Likewise when reinstalling the screen and EMF shield, it helps to have a partner who can stop the foil to the side of the screen from getting folded under the screen when you lower it back into position, ready to tape it back onto the edge of the screen.

I found that using the plastic card to remove the cover worked well in lifting the EM tape from the screen. Also step 10 & 11 appear to be reversed since you can't get to the screws until you have lifted up the display (this can only occur once you have dealt with the EM shield)

Wizbang FL, · Reply

This is a Torx T-9 on the 24" iMac Core Duo

jrmn, · Reply

Quote from jrmn:

This is a Torx T-9 on the 24" iMac Core Duo

This is also a Torx T-9 on my 20" iMac Core Duo, probably manuf'd around the same time.

Daniel, · Reply

Quote from Daniel:

This is also a Torx T-9 on my 20" iMac Core Duo, probably manuf'd around the same time.

My mistake, it's actually a T-10, but the T-9 was the only one I could get to work due to the limited angle.

Daniel, · Reply

I believe this is where the $4.95 looong T-10 screwdriver shown in the recommended tools would have come in handy. We managed to make the driver from the 54 bit set work by holding the bit driver with a vice grip, which made it possible to get down in there. The various holders that came with the set were just a hair too thick.

Justina Hayden,

These four screws are tricky to deal with. They are well recessed and hard to spot at first. A magnetised screwdriver is a prerequisite. Another way is to glue the screw heads to the screwdriver with some very weak glue, and let it almost set before trying to locate the screws back into their holes whilst re-assembling. I lost one screw somewhere inside the computer! It is alright with 3 but I hope it doesn't touch something vulnerable on the circuit board.

mindzeebeez, · Reply

Quote from mindzeebeez:

These four screws are tricky to deal with. They are well recessed and hard to spot at first. A magnetised screwdriver is a prerequisite. Another way is to glue the screw heads to the screwdriver with some very weak glue, and let it almost set before trying to locate the screws back into their holes whilst re-assembling. I lost one screw somewhere inside the computer! It is alright with 3 but I hope it doesn't touch something vulnerable on the circuit board.

Try sticking the screw onto the driver with a tiny piece of blu-tac. Worked for me.

Bob, · Reply

I found it easiest to lie the computer on its back and rest all four screws in the display. Then all you have to do is lower the display slowly and evenly. The tricky part with this method is to make sure the EMI shield doesn't catch on the screws on the way down.

Andrew, · Reply

If your Torx screwdriver isn't magnetized, rub the tip 8-10 times on the magnet inside the white plastic cover (the one that holds the remote to the side of the monitor). Prestro... your Torx screwdriver is now magnetized!

John Way, · Reply

The lower left screw of the display can be sometimes reached directly from the corner rather through the hole.

Bob, · Reply

If you remove the inverter wires after dealing with the EM shield you can flip the display without detaching the LCD data cable. Use the foot of the iMac (with a towel to protect the display) to hold the display while you work inside.

Wizbang FL, · Reply

The 17" model is nearly identical until this point. You will not have to disconnect on the 17" model for either Step 15 or Step 16.

robino, · Reply

I would mark the top of the large inverter cable connectors somehow, with a marker or pencil. My connectors had writing on the bottom, not the top as pictured, and I bent the pins trying to reinsert it incorrectly since the top and bottom look similar. Nearly all the other connectors have an obvious top and bottom.

Marko, · Reply

You don't need to peel off the display from the top. Just lean it toward a wall etc. in a perpendicular angle. If you don't move the mac while you perform the following steps, it won't flip or fall down. You can also save step 15 this way, as the wires are long enough to stay connected.

Martin, · Reply

Why peel it off? I just left it there in the perpendicular position leaning against the wall. Didn't annoy me at all when I changed the hard drive.

alex, Jul 02 2012

alexanderfaussner, · Reply

I've seen a few people comment having found their Airport dead after hard drive swap. It's really easy to rip off the wire from Airport antenna (up there nearby the mic and camera, to the left from them). The wire goes through the holes of upside EMI shielding and raising the display too high while trying to peel the shielding off can yank the wire so it gets loose from the soldering.

Tee, · Reply

I only had one of these connectors on the Airport extreme card (in the lower position).

Ed Schrank, · Reply

I am nearly certain I put the same connectors back in the same positions but am hoping it doesn't matter as this wasn't addressed as important to remember. Look for an update note if my airport doesn't work right away.

bhoffs, · Reply

In fact it is easier to unscrew (T6) the metallic support and leave the card attached to the cables

Destouches Philippe, · Reply

Mine was assembled with the Bluetooth connector ran such that it precludes removing the speakers completely, meaning step 28 had to be done while I was over there.

Carl Pearson, · Reply

Apologies for the ignorance, but would using a spudger on something like the Bluetooth antenna connector necessarily break it? Will some special glue be required to re-attatch? I will definitely take this challenge up (better than buying a new computer and very rewarding), but it's little things like that that give me pause.

projectjce, · Reply

when I was removing the one long coarse-thread (yellow one), its support beneath it broke. I was very careful actually but I think these things unavoidable if you are threading an old computer (I am using it after 1 week its release)

so I put some glue (very very little quantity) in its remaining hole, just to keep the screw in that hole

joleisa, · Reply

View Statistics:

Today: 4

This Week: 46

This Month: 491

All Time: 39,397