HT201191: Install memory in an iMac

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axk2

Q: Memory Issues iMAC

I have a Mid-2011 iMAC. I have 4GB in each of the memory top slots (Total 8 GB). I loaded the old 2GB memory in the lower slots (Total 4GB). The computer did not boot and emitted an "airplane about to stall" sound. I removed the lower slot memory and the computer booted. Does all memory in slots have to be equal? Do I need to put 4GB memory modules in the lower slots as well? Thanks

mac, Mac OS X (10.4.9)

Posted on Sep 1, 2013 7:49 AM

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Q: Memory Issues iMAC

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  • by Frank Caggiano,

    Frank Caggiano Frank Caggiano Sep 1, 2013 8:00 AM in response to axk2
    Level 7 (25,782 points)
    Sep 1, 2013 8:00 AM in response to axk2

    The memory does not have to be equal and the location of the sticks in the slots does not matter.

     

    What you did should work so either one or both of the old sticks is bad ( could be an issue if they were not stored and handled right) one of the slots is bad or you did not have the memory firmly inserted into the slot.

     

    You will have to work this slowly, remove all memory ad add one of the 2 gb sticks in at a time to make sure they both work and then begin adding in the 4gb sticks to see what configuration fails.

     

    Just be sure you handle the sticks carefully and be aware of static. You can easily ruin a stick without even realizing it.

     

    regards

  • by babowa,

    babowa babowa Sep 1, 2013 8:02 AM in response to axk2
    Level 7 (32,034 points)
    iPad
    Sep 1, 2013 8:02 AM in response to axk2

    No, it does not have to match all the way around - you did it right: the two modules next to one another should match. I've had "mismatched" modules in my iMac for two years: the two original 2 x 2 GB in the top two slots, and added 2 x 4 GB in the bottom slots (total of 12 GB).

     

    To see if the originals are bad or not seated correctly, you might want to test by removing the 4 GB and putting in the originals instead. If that works, add the 4 GB on the bottom. It could be either one or more of the slots or one or more of the modules - the only way to figure it out is by process of elimination. And, make sure that they are seated properly - click into place.