RAM problems iMac 20' Early 2008

Discussion in 'iMac' started by neasuciu, Dec 12, 2015.

  1. neasuciu macrumors newbie

    neasuciu

    Joined:
    Jun 21, 2009
    Location:
    Bucharest, Romania
    #1
    Hello!
    I have an iMac which i replaced originally RAM (1GB) with 2 x 2 Gb Corsair Kit.
    A few days ago i noticed that my computer boots very slow (at least 1:30 minutes from the moment i press the power button until i can start using it).
    So i tried to start Apple Hardware Test from the OS, of course without success; then i used the dvd disc 1 and after a few seconds after the AHT started i got an error
    “Alert! Apple Hardware Test has detected an error.
    4MEM/4/40000000: 89c3dca8”
    So i would like to know:
    1.What is the problem?
    2.What can i do to solve the problem
    I would like to say that the system is freshly installed, the HDD was entirely formatted.
    Also i took off the RAM plates i cleaned it and i blow the slots so that the dust will dissipate.
    Thanks a lot!
     
  2. rkaufmann87 macrumors 68000

    rkaufmann87

    Joined:
    Dec 17, 2009
    Location:
    Folsom, CA
    #2
    RAM can and does fail, remove the Corsair RAM and install the original RAM and see if it boots (you don't say what version of OS X is installed. If it's a version that requires more than 1GB, then replace the RAM with either Crucial (buy direct) or OWC from www.macsales.com. Upgrade it to 6GB which is what your machine can accommodate.
     
  3. DeltaMac macrumors 604

    DeltaMac

    Joined:
    Jul 30, 2003
    Location:
    Delaware
    #3
    Another tip: If the original RAM works (or you don't have other RAM to try), simply try reseating your Corsair RAM sticks. Swap them between the slots, and reseat firmly. If the RAM has been installed for several years, then I would re-seat, then eject, and reseat again. Again, the seating can take a really firm push. After the reseat, boot to your AHT again. Run both the standard and extended tests.
     
  4. neasuciu thread starter macrumors newbie

    neasuciu

    Joined:
    Jun 21, 2009
    Location:
    Bucharest, Romania
    #4
    Well, My computer starts every time, so the problem is not if It Boots or not its on The time It Boots and the fact that sometimes It takes a lot of time untill It opens a web page or an Excel document.
     
  5. DeltaMac macrumors 604

    DeltaMac

    Joined:
    Jul 30, 2003
    Location:
    Delaware
    #5
    You said in your first post that your hardware test reported an error.
    That error, beginning with 4MEM, is a RAM error. It may be that your iMac is not reporting the memory properly now.
    Try different RAM, or simply reinstall your original memory - if you still have it - It is an easy thing to try. If you don't have any other memory, then you can often fix the error by reseating the RAM that you have now.

    If your iMac is not reading the RAM properly, it can cause a slowdown, sometimes even locking up. Reseating your installed RAM may help, or even fix the problem completely.
    Be sure to boot to the AHT, and run the test. It may pass after reseating the memory.
     
  6. rkaufmann87 macrumors 68000

    rkaufmann87

    Joined:
    Dec 17, 2009
    Location:
    Folsom, CA
    #6
    The test is not wrong, it indicates that you have failed or failing RAM. It's time for it to be replaced.
     
  7. DeltaMac macrumors 604

    DeltaMac

    Joined:
    Jul 30, 2003
    Location:
    Delaware
    #7
    Absolutely.
    But, try a reseat first, then test again. If you still get a failure, then replace the RAM (both sticks)
     
  8. neasuciu thread starter macrumors newbie

    neasuciu

    Joined:
    Jun 21, 2009
    Location:
    Bucharest, Romania
    #8
    Hi, again. I did the following tests
    1. remove one piece of memory, run AHT, i got the following error
    Alert! Apple Hardware Test has detected an error.
    4MEM/4/40000000: 89c3dce8
    so another error, probably because it was in another slot
    2. the same piece, i install it in another slot and i got another error, see picture attached.
    3. removed that piece, install the second one, performed standard AHT, everything was ok; then i performed extended AHT test, and after 45 minutes everything was ok
    4. i switched again the slot, then performed the AHT, everything was ok.
    SO, bottom line, one of the RAM is bad. I need another piece.
    The curious thing was that the system booted with the bad RAM only. So, my questions now are:
    1. should i buy the same type? i mean at the manufacturer (corsair)
    2. Apple says that for my iMac 4 GB is maximum supported but i saw at some sites that 6 GB is actually maximum supported. So, 4 or 6 GB?
    3. should i buy another kit of 2 x 2 GB? Or is it ok to buy only one 2 GB (or 4 GB)?
    4. Until i buy a new RAM should i use only the 2 GB piece or is it ok to use the other 2 GB which is having problems.
    Thank you for your help!
     

    Attached Files:

  9. DeltaMac macrumors 604

    DeltaMac

    Joined:
    Jul 30, 2003
    Location:
    Delaware
    #9
    !. Corsair is OK. Many posters here prefer Crucial, or getting RAM from other sites, such as OWC.com, that are known to support Macs well.
    Some also like Data Memory Systems for good, compatible memory
    2. You can upgrade to 6GB, it is supported.
    3. You could replace the one stick. But, you already have one failure. If you are purchasing new, get both new.
    Get the same, there will be a (slight) speed advantage with having both sticks the same capacity. But, you may get slightly better performance because you have more memory installed. The important task is to get memory that works for you :D
    The DMS.com link has memory for your iMac, single stick of 4GB. Prices are good, too. I don't have any idea if they will ship to your country. That may be an issue for you. You can check at various sites, or go with a site that you have used before.
    4. You can use the single 2GB stick, and that may give you a better working computer, if the memory is your only issue. You should see that difference immediately with only the good stick installed.

    I hope this information helps you!
     
  10. neasuciu thread starter macrumors newbie

    neasuciu

    Joined:
    Jun 21, 2009
    Location:
    Bucharest, Romania
    #10
    Hi again!
    I found both types of products, in my country.
    I found a 4 GB plate and 2 x 2 GB kit.
    Thank you very much for helping me!
     

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