New RAM Not Showing

Discussion in 'Mac Basics and Help' started by Stussey, Apr 22, 2009.

  1. Stussey macrumors newbie

    Joined:
    Apr 22, 2009
    Location:
    Decatur, GA
    #1
    I've looked through these boards and a couple others and still haven't found a solution to my problem.

    I had 2G orignal RAM installed on my dual 2.3G G5. I bought a 2G kit from Kingston and another 1G that came out of my work computer. The 2 original gigs were in the inside slots. I added the 2G to the 2 open slots on top and the other gig to the lower slots. It didn't read them. I took all the RAM out and put the 2G into the top inside slots, the the 1G in the lower inside slot, it showed 2G.

    I shut it down, added the 2 orginal sets in the open slots. I reset the PRAM/VRAM as was suggested and it still only shows 2G RAM. It's showing in slots 0-3 but not 41-44.

    I'm not sure what else to do.

    Any ideas how I can get all the RAM working?

    thanks in advance,
    Stussey
     
  2. madog macrumors 65816

    madog

    Joined:
    Nov 25, 2004
    Location:
    Korova Milkbar
    #2
    Here's Apple's info for adding paired RAM http://support.apple.com/kb/HT2248. If you didn't know, it has to be paired RAM. 2 1GB chips, 2 512's, of the same speed. You can't just place a single chip in it by itself.

    If I get what you're saying, then you have to place the RAM in order, i.e., first paired RAM in the inside slots, then the next RAM in the second slot, then third and so on from the inside out (depending on how many your G5 has,). If you are placing the first pair in the inside slots, and then the second pair on the outside slots (assuming you have more than 4 slots), you are bypassing the middle slots.
     
  3. Stussey thread starter macrumors newbie

    Joined:
    Apr 22, 2009
    Location:
    Decatur, GA
    #3
    They're all matched pairs. I've got 8 slots, all the slots are filled, but only the 2 inner ones are showing. I've got 3 pair of 512, and 1 pair of 1G.

    The 2G are brand new. 2 pair (1G each) are the original RAM. The last pair(1G) came out of a G5 at work. It worked there and is the same speed,etc.
    I put the 2G pair in the top inside slot. The other pair from work in the lower inside slot. The 2 original pairs are now in the outer slots. All 8 slots are filled with matched pair. The problem is only DIMM's 1-3 are reading.

    The ones that aren't reading I know worked. They were working until I moved them. I've tried resetting the PRAM, that didn't work. Other than double checking to make sure they are all the way in, which I heard the click, I was wondering what else I could do.

    thanks for your response,
    Stussey
     
  4. rpaloalto macrumors 6502a

    rpaloalto

    Joined:
    Sep 19, 2005
    Location:
    Palo Alto CA.
    #4
    I think with the G5, the Pair refers to top and bottom.
    First pair would go in slot one of top card, and slot one in bottom card.

    Just continue with this order. Beginning with your largest ram modules on the inside slot, The one closest to the motherboard.
     
  5. madog macrumors 65816

    madog

    Joined:
    Nov 25, 2004
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    #5
    Hmmm, and you say that now it doesn't matter what RAM is in those middle slots, they just don't work at all? Even with known working sticks in there?

    I would use some compressed air in those slots (don't hold the can upside down or tilt it too much!) if you have some. Also, when you reset the PRAM, did you hold the keys down for 3 chimes (restarts)?

    If you've done all that.... I'm not too sure at this point.

    I'm wondering if the G5 HAS to be filled correctly from the inside out, or if you can (if you haven't yet, my reading comprehension is bad today) test out those middle slots with the Apple RAM to see if the machine will even boot up at all.

    edit: removed this section for failing at reading again.
     
  6. Stussey thread starter macrumors newbie

    Joined:
    Apr 22, 2009
    Location:
    Decatur, GA
    #6
    the inside slots are the ones working, it's the outer ones(closest to the optical and bottom) that aren't reading. The RAM that is in those slots worked. I'll start by making sure everything is clean and try slot by slot.

    I read that when resetting the PRAM it was 2 chimes, but if 3's the charm, I'll try that.

    thanks for all your help,
    Stussey
     
  7. madog macrumors 65816

    madog

    Joined:
    Nov 25, 2004
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    #7
    I've always done 3, heard 4, Apple does say 2 though (since I double checked just now). So that shouldn't be necessary at this point (but don't worry if you already did it, I've done 3 chime-PRAM-resets on several dozen Macs in my life and it's never had a bad effect).


    Regardless, PRAM might not be the issue. It definitely isn't a likely issue, but those slots might have "gone bad" for one reason or another, though I don't think we've exhausted all possibilities just yet.

    You could also reset the PMU, which could have an effect on malfunctioning ports amongst other things (I've never used it for this particular problem, but if done properly, couldn't hurt). On the G5's I think it's always located on the logic board, underneath the RAM slots and is a little grey button. Here's the info from Apple http://support.apple.com/kb/HT1939 which has instructions on what to unplug, how it's done and where the button is. One thing I do know is that you NEVER want to push that button twice in one sitting (so don't hit it again even if you think you missed it the first time).
     
  8. Stussey thread starter macrumors newbie

    Joined:
    Apr 22, 2009
    Location:
    Decatur, GA
    #8
    So I started the process of elimination. I ended up putting the original RAM back in slot 1. I put the 1G pair I got from work in slot 2. Those work fine. I put the next gig pair, that did work before in slot 3. No go.

    I sprayed air, cleaned it out, let it dry and still no go. I'm going to take the 2G pair to work. and take the other gig pair out and bring them home. That way I'll have all the slots filled with RAM I know works and then I'll reset the PMU.

    You said never hit the PMU button twice, not that I did, but say I reset it after I put the other sticks of RAM in, when would be the next safe time to reset it?

    thanks again for your help
    Stussey
     
  9. madog macrumors 65816

    madog

    Joined:
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    Location:
    Korova Milkbar
    #9
    Apple states that it's OK to do it again after you restart your computer and shut it down again, just never twice in one go. So if you reset the cuda (pmu), put in some sticks, restart the computer to check what it recognizes, then shut it down you can reset the cuda again.
     
  10. Stussey thread starter macrumors newbie

    Joined:
    Apr 22, 2009
    Location:
    Decatur, GA
    #10
    Is there a way other than the computer not reading the sticks right to know if they're a matched pair. They were only showing as 1G total not 2G. I've never had problem with Kingston before.

    Other than if it reads the RAM is there a way to check if the slots are actually working? Or just keep trying different RAM in them?

    thanks again,
    Stussey
     
  11. madog macrumors 65816

    madog

    Joined:
    Nov 25, 2004
    Location:
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    #11
    Didn't even think of this before, but the Hardware test on your original system discs. I believe you insert one and hold down "D" (instead of C) to begin it. It should have a label on the disc stating as such.

    The hardware test is not perfect. Pretty much if it reports a failure, then it's correct, but then again everything isn't necessarily working if it reports that everything is fine. False-positives I suppose.
     
  12. Stussey thread starter macrumors newbie

    Joined:
    Apr 22, 2009
    Location:
    Decatur, GA
    #12
    I ran the hardware test. It said invalid memory access @
    SRR0:0000000.00f4e8e8
    SRR1:1000000.0003030

    If I know all the sticks worked before I added this one, what does this mean?

    thanks again,
    Stussey
     

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