Results 1 to 6 of 6
  1. #1


    Member Since
    May 20, 2006
    Posts
    41
    Specs:
    PowerMac G5 Dual 2.0Ghz, 250GB Hard Drive, 4GB RAM, GeForce FX5200, iPhone 3G 8GB
    iMac 333 Memory Upgrade Problems
    I have an iMac G3 333 system. I bought it from someone who said they had put a 512MB upgrade inside of it. When I booted the system up, it only read 320MB (1x64, 1x256). I opened the system to upgrade the HD from 6GB to 20GB, only to find out that there was a 512MB PC133 chip in there. So I assumed that this system couldn't read anything over 256MB, I installed a 256MB PC133 chip. Now my system reads 192MB. Why is it only recognizing half of the memory??

    Also, I installed my Quantum Fireball 20GB hard drive I pulled out of my Powermac G4 AGP Graphics and it wont boot to it. I can boot a CD and install Mac OS X, but when I restart after installation, it looks for a CD.

  2. #2

    cradom's Avatar
    Member Since
    Feb 14, 2004
    Location
    Groves, Texas
    Posts
    4,551
    Specs:
    21in. iMac 10.11 --- HP win 10
    As far as the HD, you have to partition the drive so there is an 8 gig partition first (slightly less than 8), and the rest second. Install X on the first partition.
    There is a limitation in the rom on boot partition size on the older imacs.

    The 333 can use 512mb. Maybe you have a bad mem stick?
    Delusions are often functional. A motherís opinions about her childrenís beauty, intelligence, goodness, et cetera ad nauseam, keep her from drowning them at birth.
    -Lazarus Long

  3. #3


    Member Since
    May 20, 2006
    Posts
    41
    Specs:
    PowerMac G5 Dual 2.0Ghz, 250GB Hard Drive, 4GB RAM, GeForce FX5200, iPhone 3G 8GB
    Both the 512MB and the 256MB are showing up only half of what they are supposed to. I put the 512MB in my ibook G3 and it worked fine. Second, I partitioned the HD, but it's still not booting. Do I need to change the jumper settings? Again, I can hold "c" and install the OS, but when I go to restart, it comes up with the "?" and can't boot the system.

  4. #4

    cradom's Avatar
    Member Since
    Feb 14, 2004
    Location
    Groves, Texas
    Posts
    4,551
    Specs:
    21in. iMac 10.11 --- HP win 10
    Make sure the drive jumpers are set to CS or master. What version of X are you installing? The 333 can only run Panther without using something like XPostFacto.

    The 512mb stick will not work in a 333. It takes 2 256 sticks to get 512. (and the second one, under the cpu, is a special low profile one).
    Dont know why it's not reading the 256.

    I've upgraded 2 Rev D 333 imacs to 512 without any problems.
    Delusions are often functional. A motherís opinions about her childrenís beauty, intelligence, goodness, et cetera ad nauseam, keep her from drowning them at birth.
    -Lazarus Long

  5. #5
    MacHeadCase
    Guest
    Yeah it would appear that some G3 iMac models accept more RAM while others do not. From iMac G3/333 (Rev. D) - code name: Lifesavers:

    RAM: 32 MB, expandable to 384 MB using SO-DIMM SDRAM (3.3V, unbuffered, 64-bit, 144-pin, 100 MHz or faster, 10ns) in two DIMM sockets (256 MB on top, 128 MB on bottom), top DIMM socket accepts 2" DIMM, bottom socket takes 1.5" DIMM
    * The exact amount a Rev. A-D iMac can be upgraded varies from unit to unit. We have field reports of some models accepting 256 MB modules in both memory socket and reaching 512 MB - and other reports of early iMacs that won't work at all with 256 MB modules. There appears to be no way to know in advance whether a particular iMac will work with a certain sized memory module.

  6. #6


    Member Since
    May 20, 2006
    Posts
    41
    Specs:
    PowerMac G5 Dual 2.0Ghz, 250GB Hard Drive, 4GB RAM, GeForce FX5200, iPhone 3G 8GB
    Yeah I fixed the HD problem, the system only boots it if set to master, not CS. As for the RAM it doesn't make sense. I understand that a 512MB chip isn't compatible, but it was reading 256MB when that chip was in there, so you'd think that by adding a 256MB chip, it would take in the full 256MB, but it only reads half (128MB). I'm getting 192MB right now (64MB bottom, "128MB" top). There isn't much I can do I guess, I have four PC133 256MB chips and none of them are registering the full 256MB when installed. I'm running OS X 10.2 and it's running fine right now.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Problems w/ memory upgrade
    By crooked in forum Apple Notebooks
    Replies: 4
    Last Post: 08-21-2008, 01:52 AM
  2. Memory Upgrade Problems
    By rocksteadyvybes in forum Apple Notebooks
    Replies: 4
    Last Post: 10-02-2007, 08:41 AM
  3. Trying to upgrade imac 333 with OS 9.2.1 to OS X
    By Joebell in forum Apple Desktops
    Replies: 5
    Last Post: 03-02-2005, 11:22 AM
  4. Upgrade iMac 333 to OS X?
    By syc007 in forum Apple Desktops
    Replies: 7
    Last Post: 05-19-2004, 09:34 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •