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Introduction

Upgrade your hard drive for more storage space!

This guide also includes steps to upgrade your iMac's hard drive with a SSD. It describes how to install the SSD's temperature sensor so that the Mac's fans will operate at the correct speed.

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.

    • Stick a heavy-duty suction cup near each of the two top corners of the glass panel.

    • To attach the suction cups, first position the suction cup with the movable handle parallel to the face of the glass panel (as highlighted in the second picture).

    • While lightly holding the suction cup against the glass, raise the movable handle until it is parallel with the other handle (as highlighted by the third picture).

    • If your suction cups refuse to stick, try cleaning both the glass panel and the suction cup with a damp soft, lint-free cloth. (Dampen with distilled water, and if needed, an equal ratio of distilled water and white vinegar for best results.)

    • Do not use the suction cups to carry the display glass because if one of them fails to stick, you could drop the screen and break it.

    • The original iMac box makes a good place to store the glass panel. Otherwise, a padded horizontal surface, like a towel on a desk will do nicely.

  1. Gently lift the glass panel perpendicular to the face of the LCD enough to clear the steel mounting pins attached along the underside of the top edge of the glass panel. Pull the glass panel away from the lower edge of the iMac and carefully set it aside. Don't use the suction cups to carry the glass panel—if either one loses its grip, the panel could fall and break.
    • Gently lift the glass panel perpendicular to the face of the LCD enough to clear the steel mounting pins attached along the underside of the top edge of the glass panel.

    • Pull the glass panel away from the lower edge of the iMac and carefully set it aside.

    • Don't use the suction cups to carry the glass panel—if either one loses its grip, the panel could fall and break.

    • After setting the glass panel down safely, be sure to release the suction cups, as the suction force over time, can crack the glass.

    • During reinstallation, be sure to meticulously clean the inside of the glass panel and the face of the LCD as any dust or fingerprints trapped inside will be annoyingly visible when the machine is turned on.

  2. Remove the eight T10 Torx screws securing the LCD to the outer case.
    • Remove the eight T10 Torx screws securing the LCD to the outer case.

  3. Carefully lay the iMac stand-side down on a flat surface. Due to tight tolerances, you will have to use a thin hooked tool to lift the display out of the outer case. As seen in the third picture, we made one out of a bent paperclip. Use a thin hooked tool to lift one side of the top edge of the display by its steel outer frame.
    • Carefully lay the iMac stand-side down on a flat surface.

    • Due to tight tolerances, you will have to use a thin hooked tool to lift the display out of the outer case. As seen in the third picture, we made one out of a bent paperclip.

    • Use a thin hooked tool to lift one side of the top edge of the display by its steel outer frame.

    • After lifting the top edge of the display on one side, hold it out of the outer case while you use a hooked tool to lift the other side. A pencil or pen can be placed under the top edge of the display, parallel to the top edge and extending past the edge of the computer, to keep the first side propped up while lifting the second.

    • Do not lift the top edge of the display out of the outer case too far, as several short ribbon cables still connect the two components.

  4. Use a pair of tweezers to pull the vertical sync ribbon cable out of its socket on the LED driver board near the top left corner of your iMac. On some iMacs this may not be a ribbon cable but four separate, very fine and very fragile wires. Be very careful, if the tweezers slip off the plug, you will very likely pull a wire out of the assembly.
    • Use a pair of tweezers to pull the vertical sync ribbon cable out of its socket on the LED driver board near the top left corner of your iMac.

    • On some iMacs this may not be a ribbon cable but four separate, very fine and very fragile wires. Be very careful, if the tweezers slip off the plug, you will very likely pull a wire out of the assembly.

  5. Rotate the display out of the outer case enough to disconnect the LED backlight power cable from the LED driver board.
    • Rotate the display out of the outer case enough to disconnect the LED backlight power cable from the LED driver board.

  6. Squeeze the two display data cable connector arms together to unlock it from its socket on the logic board.
    • Squeeze the two display data cable connector arms together to unlock it from its socket on the logic board.

    • Pull the display data cable connector away from its socket on the logic board.

    • Be very careful when disconnecting this cable as both the cable connector and logic board socket are extremely fragile. When reconnecting the cable later, use as little force as possible.

  7. Lift the display for enough clearance to disconnect the LCD thermal sensor cable connector from its socket on the logic board.
    • Lift the display for enough clearance to disconnect the LCD thermal sensor cable connector from its socket on the logic board.

    • If your fan is spinning full speed after completion, check this connection or the hard drive's thermal sensor cable. The thermal sensor connector socket is very fragile, so be very careful when you connect back the sensor cable.

  8. Carefully pull the display toward the top edge of your iMac and lift it out of the outer case.
    • Carefully pull the display toward the top edge of your iMac and lift it out of the outer case.

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  10. Before disconnecting the thermal sensor cable, take note of its orientation. It is extremely important to reinstall the connector in the current orientation so the fans will not run at full speed. If you have multiple pins on your replacement hard drive, put the connector closest to the SATA connections and closest to the PCB board. Disconnect the thermal sensor, SATA power, and SATA data cables by pulling their connectors away from the sockets on the hard drive. Disconnect the thermal sensor, SATA power, and SATA data cables by pulling their connectors away from the sockets on the hard drive.
    • Before disconnecting the thermal sensor cable, take note of its orientation. It is extremely important to reinstall the connector in the current orientation so the fans will not run at full speed. If you have multiple pins on your replacement hard drive, put the connector closest to the SATA connections and closest to the PCB board.

    • Disconnect the thermal sensor, SATA power, and SATA data cables by pulling their connectors away from the sockets on the hard drive.

  11. Remove the two T10 Torx screws securing the upper hard drive bracket to the outer case.
    • Remove the two T10 Torx screws securing the upper hard drive bracket to the outer case.

  12. Slightly rotate the hard drive away from the outer case. Lift the hard drive off its two lower positioning pins and remove it from the outer case.
    • Slightly rotate the hard drive away from the outer case.

    • Lift the hard drive off its two lower positioning pins and remove it from the outer case.

  13. Remove the two T8 Torx screws securing the upper bracket to the hard drive.
    • Remove the two T8 Torx screws securing the upper bracket to the hard drive.

    • Remove the upper bracket from the hard drive.

  14. Remove the two T8 Torx pins from the other side of the hard drive.
    • Remove the two T8 Torx pins from the other side of the hard drive.

  15. Carefully peel off the piece of EMI foam attached to the front of the hard drive.
    • Carefully peel off the piece of EMI foam attached to the front of the hard drive.

    • Don't forget to transfer this to your new hard drive.

  16. Only follow the next ten steps if you are replacing your hard drive with an SSD kit. Depress the enclosure's front plate latch with your finger. While holding the latch down, swing the plate out. Remove the front plate.
    • Only follow the next ten steps if you are replacing your hard drive with an SSD kit.

    • Depress the enclosure's front plate latch with your finger. While holding the latch down, swing the plate out.

    • Remove the front plate.

  17. Line up the small SATA connectors so that the narrow side of the connector on the SSD matches the narrow side on the enclosure connector. Slide the drive in through the front of the enclosure until the SATA connector is fully seated. The SSD connects  with the enclosure in only one way. If the connectors are not lining up, rotate the SSD and try again.
    • Line up the small SATA connectors so that the narrow side of the connector on the SSD matches the narrow side on the enclosure connector.

    • Slide the drive in through the front of the enclosure until the SATA connector is fully seated.

    • The SSD connects with the enclosure in only one way. If the connectors are not lining up, rotate the SSD and try again.

  18. You may optionally install two Philips #1 screws that came with the enclosure kit to secure the SSD in the enclosure.
    • You may optionally install two Philips #1 screws that came with the enclosure kit to secure the SSD in the enclosure.

  19. Plug the included sensor-enabled SATA power cable into the wide side of the enclosure's SATA connector. The cable is keyed to connect in only one way. If you can't connect the cable, rotate it 180°, and try again.
    • Plug the included sensor-enabled SATA power cable into the wide side of the enclosure's SATA connector.

    • The cable is keyed to connect in only one way. If you can't connect the cable, rotate it 180°, and try again.

  20. Peel the backing off of the adhesive back of the small temperature sensor board. Adhere the temperature sensor board to an exposed, metal area of the surface of the SSD, as close as possible to the SATA connector. Fold the excess temperature sensor wires so that they are out of the way while you install the enclosure.
    • Peel the backing off of the adhesive back of the small temperature sensor board.

    • Adhere the temperature sensor board to an exposed, metal area of the surface of the SSD, as close as possible to the SATA connector.

    • Fold the excess temperature sensor wires so that they are out of the way while you install the enclosure.

  21. Install the mounting pins from the old hard drive onto the sides of the enclosure.
    • Install the mounting pins from the old hard drive onto the sides of the enclosure.

    • The holes on the enclosure may not be threaded, so screwing the mounting pins into them may require extra effort. Take your time and screw them in slowly, making sure they go in straight.

  22. Attach any mounting brackets removed from the old hard drive onto the enclosure. Attach any mounting brackets removed from the old hard drive onto the enclosure.
    • Attach any mounting brackets removed from the old hard drive onto the enclosure.

  23. Connect the iMac's SATA power cable to the new temperature-capable SATA power cable. Route the SATA cables where they will not interfere with any other components.
    • Connect the iMac's SATA power cable to the new temperature-capable SATA power cable.

    • Route the SATA cables where they will not interfere with any other components.

  24. Connect the iMac's SATA data cable to the enclosure's SATA data connector. Connect the iMac's SATA data cable to the enclosure's SATA data connector.
    • Connect the iMac's SATA data cable to the enclosure's SATA data connector.

  25. Find a connector on the motherboard labeled HD TMP or HDD TEMP. If you have trouble locating it, trace the two-wire temperature cable you disconnected from the old hard drive. If the previous temperature cable is still connected to the board here, disconnect and remove it.  You will no longer need it.
    • Find a connector on the motherboard labeled HD TMP or HDD TEMP.

    • If you have trouble locating it, trace the two-wire temperature cable you disconnected from the old hard drive.

    • If the previous temperature cable is still connected to the board here, disconnect and remove it. You will no longer need it.

    • Connect the temperature sensor's two-wire red-black cable to the motherboard plug labeled HD TMP or HDD TEMP.

    • The connector is keyed to fit in one way only. If it seems like the connector is not fitting the socket, flip the connector and try again.

    • Route the excess wire so it does not interfere with any other components.

Conclusion

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

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78 Comments

While putting the system back together, I recommend untaping and removing the vertical sync cable from the back of the led screen. Plug it back into the LED Driver board and then into the back of the screen. Reapply the tape and continue reassembling as normal. It is far easier to plug it back into the screen than into the driver board through such a small gap.

Evan - Reply

Wow! That's a great tip... I looked at doing this and thought it would be a hassle but if you said it is easier than doing it taped than it must be easier. I'm going to do this time. Thaanx

Ronald Joseph -

My hd failed and i used this guide to replace it with the same model. The problem i'm stuck with now is installing os x again. The installation starts and goes on for a while, while the hard drive makes a weird clicking noise. Then randomly the installation fails and asks to try again. I've done this ten times now.

I'm not here to rant though, i've some useful tips as well.

Instead of buying suction cups, i used a vacuum cleaner inserted into the back of a plastic container to create more pressure per inch. Also used duct tape on edges of the container to create more friction and not damage the glass. Although later i noticed you could wedge the sharp edge of a knife between the glass and the case and widen the gap with a fingernail, then pull the glass out completely.

A note when you're buying screw drivers... The ones with the interchangeable bits won't reach the screws on the lcd, so be prepared to fiddle with strips of paper and screws falling into the sides!

nav - Reply

Were you able to finally install the osx ?

Kul -

I'm supposing my SSD will go before my HDD, but either way this doesn't look like the inside of my 27" iMac. Help?

Thomas Donaghey - Reply

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