last question has anyone attemoted imac i7 harddrive upgrade?

Discussion in 'iMac' started by dudeofblokes, Jun 18, 2010.

  1. dudeofblokes macrumors regular

    Nov 3, 2007
    carrickfergus, northern ireland, united kingdom
    has anyone upgraded the hard drive in the 27" imac i know there is a lot of problems due to the heat sensors now being in the harddrive and each brand requires a different cable so must be replaced like for like ie seagate for seagate, samsung for samsung etc otherwise the fans cant get a accurate temperature read and kick in at full, has anyone not experiencd this and how hard is it to upgrade, i have read the ifixit tear down and looks tough but is it as hard as it looks?
  2. Hellhammer Moderator


    Staff Member

    Dec 10, 2008
  3. pdubak macrumors member

    Oct 20, 2009
    It's not too difficult with any of the aluminum iMacs.

    The things to watch for would be careful when removing the glass pane, lift it straight out. When you got that off, I put my other hand around the bottom of the screw driver when i'm removing the Bezel and the LCD Panel to prevent scratching up the LCD Panel if the screwdriver slips.

    When you get to installing the new drive, your going to probably have to salvage the Temp. sensor holder and the little foam cover that goes on top of it.

    It shouldn't matter what brand but I would stick to Seagate if it was me.
  4. TMRaven macrumors 68020


    Nov 5, 2009
  5. dudeofblokes thread starter macrumors regular

    Nov 3, 2007
    carrickfergus, northern ireland, united kingdom
    i just have seen there is a lot of problems with the heat sensor now being inside the harddrive so has to be a like for like on the brand, can understand the ssd but as it generates less heat but hear its a big problem for upgrading it.

    this is taken from

    "OWC also discovered that the "Late 2009" models use a "connector that seems to use the drive’s internal sensors" rather than an external sensor like earlier Aluminum iMac models. This means that the only way to upgrade the hard drive is to "replace the drive with another model from the same manufacturer that [OWC or another third-party has] confirmed works properly with this thermal sensor cable". OWC provides a list of compatible drives."
  6. pdubak macrumors member

    Oct 20, 2009
    I stand corrected, this is true on the latest models. I just forgot.
  7. Ace134blue macrumors 6502a


    Sep 17, 2009
    No its not hard. And no each brand doesn't need "different cables". All sata 3.0gbs cables are the same, except color at least.

    Edit: Ah, my bad i thought you were referring to sata cables.
  8. dudeofblokes thread starter macrumors regular

    Nov 3, 2007
    carrickfergus, northern ireland, united kingdom
    apple makes things tough for us lol i didnt know this until after i purchased my 2tb harddrive lol
  9. jazzhands01 macrumors newbie

    Jun 20, 2009
    I have the answer!

    Ok, so I just upgraded my 27" i5 from a seagate to a hitachi drive (7k3000 3TB) and got the thermal sensor to work believe it or not. Everyone said it was not possible, but with a little trial and error, I nailed it and my imac is working great and getting accurate HD readings.

    Here is what I did:

    I took the existing seagate cable out of the imac and noticed that there were only two pins inside the 4 pin cable end that goes into the back of the hard drive. The two pins mapped to the two pins on the far right with the clip facing up.

    On the back on my Hitachi, there are only two pins, so I broke the cable end apart using a thumbtack and removed the two female connector sockets from the cable end. So now I have two free female pin sockets on the end of the cable that goes into the hard drive. I then took some pliers and very carefully crimped down each female socket so that they would attach snugly to the two pins on the back of the hard drive. Next I took very very carefully attached those female sockets to each of the pins on the back of the drive. My first try I put the black cable on the right side and the grey cable on the left side. Fired up my iMac and had no luck - the fans still went crazy and the temp reading was nill.

    Then, I switched the female sockets to the other side, with grey on right and black on left and boom!! It works!!!!!!!!!!!!!!!!

    Lastly, I put a 1mm x 1mm piece of electrical tape between the two female sockets to prevent them from touching and shorting.

    To all those frustrated people out there that had already bought their drive only to find out about the thermal senor cable issue after the fact, you are in luck!!!!!!!!!

  10. Detosx macrumors regular

    Aug 27, 2010
    Hi jazzhands01, thank you for sharing your findings. Is this a mid 2010 model? I have been reading that without the firmware that Apple install on the hard drives (or certainly on the Seagate at least), people with the mid 2010 model have been encountering some problems just swapping out a replacement drive of the same model or even when purchasing a temp cable specific to their new drive, so I am wary at this point. What rpm is your HD fan running at when the HD is relatively idle? Also I wondered why did you upgrade the hard drive, was it purely that you were keen to up the capacity or did you find your particular Seagate sample gave off a loud bass trump-trump sound like rubber balls rolling around in the bottom of a plastic tub? I have only fitted one 3TB in a PC build for a client and though I would find it easily livable with it was one of the more vocal drives that I have fitted. Also, if you have a moment, what temperatures are you seeing under sustained read/write?

Share This Page