Introduction

When the VRAM on my early-2009 24" iMac went bad, I feared I might need to trash the machine. Some sources suggested the video card was soldered to the logic board but that may only be true of the base-model iMac. The ones with the nVidia and ATI upgrades are repairable/upgradable as illustrated in this guide.

This guide will illustrate disconnecting all cables from the logic board, removing all retaining screws from the logic board, removing the logic board, and replacing the video card.

Image 1/2: '''STOP''' at step 11 of her guide, "Lift and remove the display panel." You do '''not''' need to remove the HD to replace/upgrade the video card.
  • Begin by following the excellent existing guide on opening this model of iMac, thanks to Brittany, located here.

    • STOP at step 11 of her guide, "Lift and remove the display panel." You do not need to remove the HD to replace/upgrade the video card.

  • As Illustrated here, I chose a less-expensive alternative to the $15 suction cups to lift the glass. For less than $5 I got a pair of 3M "Command" adhesive coat hangars. They proved more than strong enough. The easy release feature came off cleanly with zero residue.

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Image 1/1: The logic board is outlined here in red. We have to remove it completely since the video card is installed on the backside. Before we do that, we have to carefully separate 17 connectors.
  • Once you've removed the LCD display from the device you can see what you're in for.

  • The logic board is outlined here in red. We have to remove it completely since the video card is installed on the backside. Before we do that, we have to carefully separate 17 connectors.

    • You can see parts of the graphics card highlighted in orange. The GPU is on the right and the dedicated heat fins are on the left, located just "downwind" of the CPU heat fins.

  • AFTER we disconnect all the wires, you need to also remove the right speaker enclosure since it covers the corner of the logic board. It's retained with one obvious screw.

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Image 1/3: Disconnect these three connectors for the HD temp sensor, optical drive temp sensor, and hard drive fan.
  • This position on the logic board has three closely-spaced connectors for the power button, ambient temp sensor, and the CPU fan. Unplug them.

  • Disconnect these three connectors for the HD temp sensor, optical drive temp sensor, and hard drive fan.

    • Each one of these three connectors has a different number of pins so you can't mix them up when reconnecting. Thanks, Apple!

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Image 1/3: You have four plugs to disconnect at this location: SATA bus, microphone, and the left and right speaker cables.
  • Disconnect the plug for the optical drive fan.

  • You have four plugs to disconnect at this location: SATA bus, microphone, and the left and right speaker cables.

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Image 1/1:
  • Take a note here how the cable for the left audio speaker (I'm pinching it) is routed loosely above the RAM slots. After you reinstall the logic board, you need to put this back in a similar style.

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Image 1/3: At last you'll disconnect the main power cord and the Hard Drive SATA cable. I photographed the top one already disconnected; be sure to squeeze the edge tabs to release the clamp hooks. The HDD SATA connector has a convenient pull tab.
  • Almost there! Time to really go wireless by disconnecting the three WiFi and bluetooth antennas. These are tiny snaps so pull gently upward. Also, sneaking in from underneath, you'll find the iSight camera cable. Unplug it. This is one to look out for when you reinstall the logic board.

  • At last you'll disconnect the main power cord and the Hard Drive SATA cable. I photographed the top one already disconnected; be sure to squeeze the edge tabs to release the clamp hooks. The HDD SATA connector has a convenient pull tab.

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Image 1/2: Long ones (2.5mm x 24mm)
  • Wires done. Now to get unscrewed. There are ten T-10 torx screws holding the logic board to the case in three different sizes:

    • Long ones (2.5mm x 24mm)

    • Short ones (2.5mm x 7mm)

    • A short one with a fine thread (2.5mm x 7mm)

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Image 1/2: Remove the two T-9 (2mm x 7mm) screws from the bottom right and left corners of the RAM slots that secure the black plastic bracket to the frame.
  • If you haven't done so already, remove the speaker assembly on the right by loosening a single T-10 (2.5mm x 14mm) screw.

  • Remove the two T-9 (2mm x 7mm) screws from the bottom right and left corners of the RAM slots that secure the black plastic bracket to the frame.

  • Now simply lift out the logic board while keeping a careful eye on all those wires you just disconnected. The heatsink fins are attached to the logic board and lift out with it.

  • Note: There is a bit of foil tape on the far right (by the audio ports) that will need to be pulled up from the case as well while you lift out the motherboard.

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Image 1/3: Flipping the board over you'll find all the back-panel connectors and some nifty copper heat piping for the CPU and GPU.
  • The logic board is moved to my padded work surface.

  • Flipping the board over you'll find all the back-panel connectors and some nifty copper heat piping for the CPU and GPU.

  • Those heat pipes flow to fins above the main blower. This is what 4 years of dust accumulation looks like. Is this the reason my VRAM died?

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Image 1/3: a third T-9 (2mm x 4mm) screw on the end of the heat sink...
  • The graphics card is retained by two T-9 (2mm x 5mm) torx screws on the GPU board...

  • a third T-9 (2mm x 4mm) screw on the end of the heat sink...

  • and the ever-present thermal sensor connector.

  • Remove/disconnect them all.

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Image 1/3: In the second photo you can see the replacement graphics card (Apple part #661-5135) I got from Impact Computers in Florida. It's a drop-in replacement. Even the adhesive foam and thermal sensor are already in place. In fact, you better not turn your back or you may forget which is which!
  • You've done it! The graphics card simply tilts up 45 degrees and slides up out of the MXM connector, heat sink and all. I'm glad I could see just how well engineered this piece of Apple hardware is.

  • In the second photo you can see the replacement graphics card (Apple part #661-5135) I got from Impact Computers in Florida. It's a drop-in replacement. Even the adhesive foam and thermal sensor are already in place. In fact, you better not turn your back or you may forget which is which!

  • You World of Warcraft players out there might agree my son and I thought the old video card makes a pretty authentic-looking Gnomish 1H axe. Glory to the Alliance! :-)

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Conclusion

To reassemble your device, follow these instructions in reverse order. This is a good time to vacuum out all that accumulated dust too!

32 other people completed this guide.

15 Comments

Any tips for selecting a replacement gfx card? How can I be sure my purchase will work?

aaaidan - Reply

Aha! The "Apple part number" from step 11 is a great clue! Searching for these cards by this part number yields many online sellers.

There were three cards that could go in this model:

* NVIDIA GT120 (256Mb): part #661-4991

* NVIDIA GT130 (512Mb): part #661-4990

* ATI Radeon HD 4850 (512Mb): part #661-5135

The ATI card is generally marginally cheaper than the equivalent NVIDIA.

aaaidan - Reply

When I bought my iMac new, I remember the ATI card being the top-of-the-line option.

Jeff Dickson - Reply

Hey Jeff

Do you think I can replace the GPU with a unit from a 2011 iMac?

Rob - Reply

If you're going to try and substitute parts, I would start with the website I bought my video card from (http://www.impactcomputers.com/apple-ima...) and see if the video card(s) for that particular 2011 iMac match any of the part numbers aaaidan shows above.

I picked out one of the 2011 iMacs at random on the website and while the actual card looks the same (size and MXM connector) the heat sink is completely different. But you could try and dismantle the heat sink from the old and new cards and swap them. I would love to know if that works. An AMD Radeon HD6750M upgrade would be sweet :)

Jeff Dickson - Reply

Hmm ok, I exchanged the cards today, but as I already feared = screen stays black...

Guess i'll have to buy a GT130

Rob - Reply

Strangely the mac is working, but screen stays black. I can hear Windows boot... maybe theres a trick with EFI flash i.e.

Rob -

Hi. I did it, but separatet the cooler from the grafic-card. Removed als that "cooling-gum" on the RAM's and cleaned the CPU with tissue-paper. Heated my kitchen oven to 200°C, waited untill temp ist reached. Then put my grafic-card inside for exact 5 Minutes. After this, open the oven, DONT TOUCH THE CARD. Switch oven to off. Wait until the card has slowly reached room-temperature. Reassemble (using the cooling-goo on the rams, and some "Wärmeleitpaste (German-word; i am lazy)" on the CPU. Press the coolerplate firmly to the card (all the goo has to be flatened, to gain contact between the cooling plate and the cpu) - Reassembled, WORKS!

For a broken-card... at least worth a try. Dont blame me if it dosent work. There are thousand of threads out there about this topic - inform yourself.

BTW: Card is a NVIDIA GeForce 8800 GS 512 MB

Heiko - Reply

Hello Heiko seems that this would only work on a 8800 (German: glaube nicht dass dies bei einer GT 130m funktioniert). But I shall give it a try

Rob -

Hi, for me the new graphic-card was to expensive. i take the card and put it in my oven for 20 min by 220 degrees. and... it works now. How long? i don't know...

Stefan - Reply

IT WORKED! I baked my card at 200°C (about 400F) for 20 minutes yesterday. Mac is runnung smoothly so far...

Rob -

I had the exact problem as described in the article. Bought a graphics board online. I could not locate any new ones, however, for a mid 2008 iMac. Followed this procedure and the referenced one for opening the iMac. Both very excellent guides. Thank you so much for posting them. I would only reiterate the part about being very careful when pulling up the outer glass. The alignment pins break off very easily. I broke 2 or 3. The good thing is that they don't seem to be essential to the screen as it is held in place very well with the magnets. Thanks again for the excellent guides!

johnnya - Reply

Awesome

Brian - Reply

Hey guys, i replace the card with a Dell G92-751-B1 M17X/M15X Nvidia GTX 260M 1GB MXM 3.0 and it works fine but gamma is too high (it is like take a look to the sun without sunglasses). I tried to low it with same programs but I cannot lower to to an acceptable level (fn f1 and fn f2 keys dont work). I install windows 7 on bootcamp and cannot install any nvidia drivers, always computer tell me that cannot install the specific driver. In mac the System Information card model correctly listed (gtx 260m). Any idea?

havell - Reply

Hi. I have a imac 24 a1225 model. Nvidia Geforce 7600 GT is compatible ?, and geforce GT210 is compatible ?. I expect an answer. Thank you

Adroid Prueba - Reply

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