9 Replies Latest reply: Feb 8, 2013 10:14 AM by rccharles
sdmeier Level 1 (0 points)

Hello All!!  I purchased an iMac from ebay 2 weeks, a G5 PPC 1.8 ghz, 2 GB RAM, & a 160 GB Hard Drive with 10.4.11. You should also know this is my first Apple product of any kind.


Here is my problem.  I had been installing a few third party apps such as Open Office and a Graphics Program and such.  Well after about a week it started to act funny and started locking up and the fan would kick into high gear.  So I figured I would just blow off the OS and reload 10.4. 


So the install went great, no problems at all.  I installed all of the updates, checking several times until there were no more and again, no problems.  I then started to look around and was going to install Open Office again and thats when the freezing started happening again just opening up Finder as an example.


A few google searches later I figured out how to replace the RAM... same problem.  I then thought OK... the hard drive is bad.  So I replaced that... Installed the OS, but this time I only installed the first set of patches to get it to 10.4.11 and again the system is freezing and the fan kicks into high gear.


I have examined the motherboard and did not see any issues.  I have blown out all the fans and made sure everything looked good.


I really don't understand what could be causing this.  The Memory was replaced, the hard drive was replaced.  I would think if the Motherboard or Processor was bad it would fail during the OS install or during the Patching, but it run fine during those tasks.  If I let it sit and don't touch it, it doesn't lockup (how do I know you ask... becasue I can come back 30 mins later and wiggle the mouse and it wakes up and the screen comes back on) but as soon as I start using it... WHAM!


Can anyone shed any light on this??

iMac, Mac OS X (10.4.11), 2 GB RAM, 160 GB Hard Drive
  • rccharles Level 5 (7,574 points)

    Early iMac g5's had problems with capacitors, power supply, and video.



      Shutdown your machine.  Hold down the shift key.  Poweron.  Wait awhile Wait awhile while you harddrive

    is being checked.


    If this works fine, you need to downgrade the video driver.



    I'd suspect capacitor problem.  You can take it to an apple store and I hear they will advize.


    Google: g5 capacitor replacement kit





  • sdmeier Level 1 (0 points)

    Thanks for the help, unfortunatly that did not help.  I looked at the capacitors and didn't see any issues, unless the guy that sold it to me, cleaned them off and pressed them back down so they werent bulging anymore, I can't see that they are bad.


    Can they still be bad even though they are not showing signs of anything?  And again,  Why only when I doing something, I still believe if this were some sort of hardware issue, it would happen during install or during patching?


    Not a good first experence with my first Apple product I hate to say.  I know you get what you pay for (I only paid $200) but still,  Very hard to troubleshoot and a waste of money I guess.

  • rccharles Level 5 (7,574 points)

    You can take it to an apple store and I hear what they will advise.


    try a user group:



    There was an extended warrenty on the 1st generation iMac g5 on the capacitor problem.


    Could replace all the capacitors.  What the heck.  get experience with soldering.


    It's the downside of the all in one design.  There are less component to swap.  It's the direction of computing.



    Is this a black or grey machine specific disc?  Could be the wrong grey disc.



  • WZZZ Level 6 (12,855 points)

    Sounds like the freezes could be heat related. Open it up again and blow out as much dust everywhere as you can. Get iStat Pro widget to check the temps and fan speeds. Note the temps when it freezes. The fans kicking into high gear suggests heat issues.




    Can they still be bad even though they are not showing signs of anything?

    Unfortunately, yes. Would need to be tested with an ESR meter. And the caps could be bad inside the power supply. Not easy to see inside there.


    If you haven't done it before, doing the soldering yourself is not recommended. Even Spudnuty, the former resident iMac G5 guru here , said he would ruin a few from time to time.


    Try an SMU reset




    Open up Console in Utilities and look around in the various logs for any messages from around the time of the freezes.

  • sdmeier Level 1 (0 points)

    You are not going to believe this...  It was the Mouse!!!  I swapped it out and now everything is fine.  I had a cheap, No Name mouse hooked to it and the wife asked if I had tried a different Keyboard and mouse... So I tried and now it's is stable. 


    WOW, one for the books for me,  I ain't never seen a mouse cause something like that.


    Thanks for everyone's help!!

  • WZZZ Level 6 (12,855 points)

    I'll be convinced it's not a coincidence when you try the old mouse again and the freezing reappears.

  • sdmeier Level 1 (0 points)

    As requested...  (Just to let you know, the machine has been powered off all day, so it'snot a heating problem.) 


    I hooked up the old mouse and within 2 Mins of use, the system locked up.  I powered it off, hooked another mouse to it... No problems.


    Hey,  Im with ya,  I have been a PC guy for 25 years and I have never seen a Mouse lock a system up,  I've see a mouse fail, but not lock up the entire system.


    Also,  Just to let you know.  The mouse has lights on the sides that light up when plugged in,  I'm not saying thats why it's locking the system up, but maybe, just maybe, it's sending bad voltage back down to the system causing it to lock up.. I don't know, but I have no other explanation.


    I have attached a couple of pics for you.



  • WZZZ Level 6 (12,855 points)

    Thanks for the feedback. Quite interesting. I'll have to remember this one for future issues with freezing.


    Here's something that would tend to agree with what you've done. I've known that peripherals can cause a variety of problems, but it's not the usual suspect for me when it comes to freezes.


    Step 2: Disconnect any external devices except mouse and keyboard. Try a different keyboard and/or mouse if you have one. Also, you might try hooking up another monitor if you have one.


  • rccharles Level 5 (7,574 points)

    If the mouse stop sending signals, the system would appear to have stopped ( unless in the middle of something ) because moving the mouse would have no effect.  Mouse pointer would not move.  It would look like a system freeze, but really a mouse freeze. 


    Good diagnotics on wife's part.


    Unless you know to hit keys like f10 or f11 special keys not on many keyboards, keyboard don't do much unles  in text input mode.


    Try mouse on anotehr system.  See if it fails. 


    PS.  Just trash the mouse & forget about it.