iMac G5 RAM problem

in Genius Bar edited January 2014
So I went to and bought 3 512 MB PC3200 DDR 184-pin Unbuffered non-ecc DIMMs. 1 of these is intended for my girlfriend's 20" iMac G5 that is sitting next to me, and 2 of these will be going into my DP 2.5 GHz G5 when it comes on friday.

So they all arrived on tuesday, and I immediately removed the back cover from the iMac, slit open the static-free bag, and stuck the chip into the iMac. Booted it up... kernel panic before it got done starting up. Rebooted... kernel panic again. Reset the PRAM, no change.

So I took out the apple-supplied RAM and it booted fine. I put one of the other crucial 512 chips in there and it still booted fine.

Question 1: why would these crucial 512 MB chips not work with Apple's 512 MB chip? I thought the iMac did not need identical chips in each slot...

Continuing on...

I bought world of warcraft as well, on Tuesday. I installed it, set up my account, started playing. It crashes a ton, and I even get kernel panics while playing. On one hand, it is a new MMO game, so while it displeases me for a game I spent that much money on to be that unstable, I can see how it might be the game's fault. On the other hand, this RAM has been nothing but trouble so far.

The finder has been a little... wonky as well. I am in the process of reinstalling World of Warcraft, and I also removed both crucial chips and replaced the original Apple RAM.

Question 2: if the system is stable now with the Apple RAM, and WoW at least doesn't cause kernel panics, is that reason to believe that crucial needs to send me new RAM?




  • Reply 1 of 6

    Originally posted by Ender

    Question 2: if the system is stable now with the Apple RAM, and WoW at least doesn't cause kernel panics, is that reason to believe that crucial needs to send me new RAM?

  • Reply 2 of 6
    Also remember that if the two modules are not the same size (mismatched) in the iMac G5, it will run in 64-bit path as opposed to 128-bit path (much better). So you now have a mismatched pair running at reduced performance (at least according to Apple's support docs).
  • Reply 3 of 6
    It sounds to me like you got sent faulty RAM.
  • Reply 4 of 6
    Looks like I have a similar problem with a brand new iMacG5 17 inch Superdrive .

    I had the RAM upgraded to 768 MB by my reseller. (promotion bundle: buy applecare and 512 MB RAM for "free" )>> Looks like Apple does not make a big deal out of this "matching RAM" business....

    After opening the box and admiring the care and attention for detail Apple has put into it's packaging, I created two accounts and I could not shut down the computer anymore because there was a "user still logged on"...

    I switched the machine off with the hardware button end then the iMac would not start up anymore. I saw a grey screen and the fan started to blow at full speed. Looks like a kernel panic...

    Then I zapped the PRAM, which seemed to work fine but the problem persisted.

    This time, all I coulmd see was a blue background and an extremely faint window in the centre of the screen ( I guess it was the log on screen ) It looked as if this screen had been on for a few months and that the image of the white window had been "burnt in" . Weird stuff...

    So I then removed the extra 512 MB, as I assumed that was the evil-doer, reinstalled OSX and....same thing...It does not allow to be shut down..

    This is irony in it's most cruel disguise as it's actually my parent's computer, and I recommended them to buy one for it's legendary build quality, ease of use and stability...

    Another weird thing is that my dad's user name was even messed up. Suddenly 3 letters in his name were missing????

    Anyways, looks like I'm going to have a chat with the Apple helpdesk this afternoon.

    Any thoughts what's going on ?

    I'm starting to think that maybe the factory delivered 256 MB RAM could be at fault...

    (edited for spelling)
  • Reply 5 of 6
    OK, after some further investigating, I discovered that I should take error reports from my folks with a grain of salt...

    The reason why my dad couldn't shut down the iMac was simply because he left my mom logged in....

    The other weird thing, his user name missing 3 letters also turned out to have a reasonable explanation. His name is simply too long to fit in the login screen so the OS replaces the middle letters by three dots...

    Now, to the real problem, the kernel panicks and the refusal to start up properly...

    Taking out the extra 512 MB RAM solved the problem. Re- inserting resulted in kernel panicks so I can now be 99.99% sure that I was given bad RAM....

    So there, the verdict

    Apple > NOT GUILTY

    * off to go and get a replacement 512 MB RAM **
  • Reply 6 of 6
    I case anyone cares, the iMac is running fine now.

    It must be quite sensitive when it comes to RAM though...

    I had to return twice to the Apple reseller because the first replacement did not work either !!!

    Anyway, everything's hunky dory right now
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