Previous 1 2 Next 23 Replies Latest reply: Jun 21, 2012 1:14 PM by Mike Sombrio
jberry Level 1 (0 points)

My iMac had two 1gig sticks of memory. When Lion installed, I needed 4 gigs.


When I put one 2 gig stick in (meaning I have 3 gigs total now), display works fine. When I add the second 2 gig stick and turn iMac on, computer is on, but display is black. I have interchanged the new memory sticks by themselves in the imac to make sure they are both fine, which they are.


Soooooo......when I have either one of the new 2 gig sticks in (either memory stick--they both work properly), the display works, but when both 2 gig sticks are in, the display is black.


My model (late 2007) indicates computer will take 4 gigs total.


Please help!!!

  • stedman1 Level 9 (69,749 points)

    This often indicates that the RAM is incorrect spec. Your iMac requires PC2-5300, 667mHz RAM.

  • Mike Sombrio Level 6 (14,955 points)

    Try resetting the SMC and pram/nvram

    To reset the SMC

    1. Shut down the computer.
    2. Unplug the computer's power cord.
    3. Wait fifteen seconds.
    4. Attach the computer's power cord.
    5. Wait five seconds, then press the power button to turn on the computer.

    To reset the pram/nvram

    1. Shut down the computer.
    2. Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
    3. Turn on the computer.
    4. Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
    5. Hold the keys down until the computer restarts and you hear the startup sound for the second time.
    6. Release the keys.
  • Mike Sombrio Level 6 (14,955 points)

    Could that be the case considering that both sticks work by themselves?

  • jberry Level 1 (0 points)

    One more item to note for the above, when both memory sticks are in and I turn computer on, I can hear/feel it come on, HOWEVER, it does not give the opening chime sound.

  • jberry Level 1 (0 points)

    Mike, I agree, the sticks must be correct specs because they both work independently and when I go into About this Mac, it show the new 2 gig stick....but when I out them both in together, no display.

  • stedman1 Level 9 (69,749 points)

    Based on the numerous posts on the forum, if the RAM is the incorrect clock speed IE: 800mHz instead of 667mHz, the computer will exhibit exactly the situation you describe.

  • jberry Level 1 (0 points)

    The RAM specs on the product box says the correct specs for (DDR2-667).


    Additionally, I have already tried each stick separately along with 1 gig in the other memory slot, and both sticks work independent of each other with the display working fine.


    Anybody with new thoughts?

  • jberry Level 1 (0 points)

    You indicated what tge RAM requirements are for my computer.  What I bought says SODIMM, 200 pin DDR2-667


    However it doesn't say anything about "PC2-5300.". Could it be something different and therefore the problem?


    It definitely is ddr2-667, just no where does it say the pc2-5300.

  • Mike Sombrio Level 6 (14,955 points)

    You should contact the vendor that you got the ram from nd inquire exactly what it is. Where DID you buy the ram and what brand is it?

    Here are your specs


    RAM Type: PC2-5300 DDR2 SDRAM

    Minimum RAM Speed: 667 MHz

    RAM slots: 2

    Maximum RAM: 4.0 GB


    By the way, I don't believe there was a llate 2007 iMac, there was only one model in 2007, the mid year model.

  • jberry Level 1 (0 points)

    Thanks Mike. I'll follow up with the store I bought it from.  (and you're right on the date of the product).

  • Mike Sombrio Level 6 (14,955 points)

    Tell me that it isn't Kingston Value Ram.

  • jberry Level 1 (0 points)

    Probably worse...the box says Centon"....never heard of them....maybe I need to return it and order on-line...who would you suggest if I do?

  • Mike Sombrio Level 6 (14,955 points)

    Personally I only use ram from Crucial, but OWC has a great reputation for quality ram and customer service.

  • Mike Sombrio Level 6 (14,955 points)

    And I would strongly suggest you return it. Mac's can be very picky about ram, it's always best to by ram that is guaranteed to work with a Mac.

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