7 Replies Latest reply: Jun 28, 2014 8:40 AM by lannoy
lannoy Level 1 (0 points)

I noticed the other day, that my late 2009 27" iMac only had 2GB of RAM displayed on the "About this Mac" splash screen. I clicked 'More Info' and discovered that, according to the system profiler memory tab, I had only one slot used and three slots empty.

As the Mac had shipped with 4GB of RAM, I was a little puzzled, so I took a look at the memory slots only to find the top two slots were used and the bottom two empty and not, as the memory tab on the system profiler suggested, that only one slot was being used.

I swapped the RAM from one slot to the other (top slots only) and I'm still being told that three slots are empty.

Does this indicate a faulty slot? Any thoughts?

  • Csound1 Level 8 (46,325 points)

    Either a faulty slot or improperly inserted or faulty chip.

  • Frank Caggiano Level 7 (25,715 points)

    You can try putting the RAM into the original unused slots and see what the system reports. Or you can try stacking them one on top of the other (rather then size by side) to see if the report changes.


    If you can get the full 4 gb  of ram to show with a different combination of slots and you are not looking to ad memory then you could continue to use the system in that configuration.

  • lannoy Level 1 (0 points)

    Thanks for the reply.

    I managed to get two new 2GB sticks and put them both in the bottom slots. So that all four slots are loaded.

    Now I've got 4GB of RAM with the system profiler telling me that I'm only using the left-hand side top and bottom slots and that the top and bottom right-hand slots are empty.

    I've tried just about every combination of sticks to slots and I get the same system profiler result:

    Left-hand side top and bottom used. Right-hand side top and bottom - empty.

    This looks like a faulty pair of slots on the right-hand side.

    Any further thoughts?

  • Frank Caggiano Level 7 (25,715 points)

    So all 4 slots have a 2gb stick in them? (which should show as 8gb)  But the system reports only 4gb installed?


    I would take out all the memory and install one stick into each slot in turn and see if one or two of the slots show up bad. Use one of the new memory stick to test this. Start with left hand top then right hand top then the same on the bottom.


    But it sounds like you have a bad slot(s).

  • lannoy Level 1 (0 points)

    Thanks again for the reply.

    Tried all that.

    When I put a single 2GB stick in the top right-hand slot my Mac won't boot up and the same for a single stick in the bottom right-hand slot.

    So no matter what configuration of sticks to slots, the maximum I can get is 4GB with the two right-hand slots always showing empty.

    Bad slots I think!

    As a matter of interest, this is the configuration I am getting with:

    1. all four slots filled


    2. with only the top and bottom left-hand slots filled and the top and bottom right-hand slots empty



    Screen Shot 2014-06-28 at 13.55.13.png



    Screen Shot 2014-06-28 at 13.55.13.png

    So if this is a faulty slot problem, what is the next step?

    As the slots are part of the logic board, this sound like an expensive fix and I don't suppose Apple will put this right at no cost either!!

    Thanks again for the interest.

  • Frank Caggiano Level 7 (25,715 points)

    Sure looks like a slot issue and you're right if it is the slot(s) then your looking at the logic board to be replaced and that will run you somewhere in the $700 range,


    If you are near an Apple store I would take the system and have them diagnose it. there will nor no charge for that even being out of warranty, and see  what they say. If it is the logic board you can at least make an informed decision as to if you want to spend the money.


    If you don't do the repair there is one possibility to make the system more useable, get two 4gb sticks. At least then you'd have 8gb of memory and only be out the cost of the memory.


    good luck



  • lannoy Level 1 (0 points)

    Yes, I think the second option is the most cost-effective.

    Annoyingly, this is the second logic board failure this year!

    First was my Macbook Pro and now this!

    However, considering I've been using Macs since 1989, I suppose two faults in 25 years ain't so bad!

    Thanks again for the support...