2 x 2Gb Crucial DDR2 PC2-6400 = Alu iMac not starting

Discussion in 'Mac Basics and Help' started by bellowing, Mar 30, 2008.

  1. bellowing macrumors newbie

    Joined:
    Mar 30, 2008
    #1
    Hi!

    I just bought 2 x 2Gb Ram from Crucial. http://www.crucial.com/store/partspecs.aspx?IMODULE=CT25664AC800

    The problem is that my Mac doesn't start if I install them both. If I keep any of the crucial ram with the original 1Gb that came with the machine it works(and the hardware test says it is everything o.k.). I tried this setup on my MacBook too and the same result. The fan starts and the screen remains black(no biping sound). Also if I leave only one of the crucial ram the mac doesn't start.

    I think the problem comes from the 800Mhz of the ram module. I know they should be backwards compatible, but... you know. Should I go and switch them with 667Mhz ones? Is this really the problem or is there something I am missing?

    ------

    Also I received a memory stick made by Adata(4Gb). On PCs the sick works fine but I cannot use it with my mac. If I want to copy something or I just keep it in the USB port, finder gives me the beach ball and says that "It was removed incorrectly". I tried to erase it or verify it with DiskUtility and the same error. Tried it on different macs - same behavior. Can I fix this?


    Thanks a lot!
     
  2. blurb23 macrumors 6502a

    Joined:
    Feb 25, 2007
    #2
    I don't know much about RAM, but I know that when I bought my upgrade kit, I bought PC2-5300. Yours is 6400. Perhaps that makes a difference?
     
  3. HLdan macrumors 603

    HLdan

    Joined:
    Aug 22, 2007
  4. CanadaRAM macrumors G5

    CanadaRAM

    Joined:
    Oct 11, 2004
    Location:
    On the Left Coast - Victoria BC Canada
    #4
    Send the 800 MHz RAM back.

    The 4 GB memory stick -- can you tell on the PC how it is formatted -- FAT32 or NTFS?
     
  5. jonbravo77 macrumors 6502a

    jonbravo77

    Joined:
    Feb 20, 2008
    Location:
    Phoenix, AZ
    #5
    Typically the speed does not matter to much. If you have a machine needing 6400 speed RAM and you get a lower speed RAM (5300 for example) all that means is that your system will only run the RAM at the 5300.

    But anything is possible :)

    Peace:cool:
     
  6. bellowing thread starter macrumors newbie

    Joined:
    Mar 30, 2008
    #6
    The memory stick is FAT32. I will try to format it NTFS and post here how it goes.

    Thanks for the help.
     
  7. bellowing thread starter macrumors newbie

    Joined:
    Mar 30, 2008
  8. CanadaRAM macrumors G5

    CanadaRAM

    Joined:
    Oct 11, 2004
    Location:
    On the Left Coast - Victoria BC Canada
    #8
    Typically -- Except some Macs are not typical. For example it's pretty well established that Penryn MacBook Pros do not work with 800 MHz RAM notwitstanding that the JEDEC standard says that they should have 667 values written in their SPDs.

    NTFS is better supported on the PC side, but it may give you issues writing to it from the Mac.
     
  9. mreg376 macrumors 6502a

    Joined:
    Mar 23, 2008
    Location:
    Brooklyn, NY
    #9
    If you went to the trouble of ordering from Crucial, with their excellent system for determining the correct RAM to order, not to mention that the Imac documentation also explains which RAM to upgrade with, why did you order PC2-6400 when the machine requires PC2-5300?
     
  10. bellowing thread starter macrumors newbie

    Joined:
    Mar 30, 2008
    #10
    I am from Romania. I just bought what I could find at a local IT store. As I knew they should be backwards compatible, I thought I was ok.
     

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