13 Replies Latest reply: Apr 18, 2011 7:46 PM by xXmatt69Xx1
xXmatt69Xx1 Level 1 (60 points)

My name Is Matt and i've had my iMac G5 for about a half a year now and only a couple minor things went wrong that i fixed with a couple steps. But I can't seem to fix this one. So one day i turned on my iMac and It booted up fine. But i noticed when i was done using it It would hang on the shutdown and I couldn't turn It off other than holding the power button. Then things got worse. I then turned it on later the next day and when I logged onto my user i had NO icons on the top left menu bar (Spotlight, Sound, Wifi, etc.), I couldn't log off i couldn't open Finder, I couldn't do anything. So i held the power button until it turned off and when i turned it back on the gray Apple logo came up and the pinwheel came up (Like Usual) but then It went to a blank blue screen. All you could see was the mouse. And sometimes instead of a mouse you see a spinning beach ball. This never happened to me before and i never updated or installed anything before this happened. I have been on 10.5.8 since I had my iMac...

Any suggestions please?


- iMac G5 17" Ambient Light Sensor
- Mac OS X (10.5.8)
- iMac G5 17" Ambient Light Sensor | 148.93 GB | 2GHz PowerPC G5 Processor | 1GB DDR SDRAM | Build 9L31a | Version 10.5.8

iMac G5 17" Ambient Light Sensor, Mac OS X (10.5.8), iMac G5 17" Ambient Light Sensor | 148.93 GB | 2GHz PowerPC G5 Processor | 1GB DDR SDRAM | Build 9L31a | Version 10.5.8
  • MGW Level 7 (27,020 points)
    Welcome to Discussions Matt - thanks for posting all your details, it saves a lot of time.

    Try resetting both the PRAM and then the SMU:

    1. Shut down the computer.
    2. Unplug the computer's power cord.
    3. Press and hold the power button for 5 seconds.
    4. Release the power button.
    5. Attach the computers power cable.
    6. Press the power button to turn on the computer.

    Once you've done that, go to Disk Utility and repair Permissions.

    Please post back with results,

  • xXmatt69Xx1 Level 1 (60 points)
    Yes I tried all of that i even tried to boot in Safe Mode. It boots the same blue screen in Safe Mode too.
  • MGW Level 7 (27,020 points)
    That would seem to suggest that your logic board has failed. I'm afraid it's time to take it in and have it looked at by a tech. However, since you have the Ambient Light, try opening the back and look for swollen or leaking caps (little soda cans), their tops should be perfectly flat. If they are not, you have found your problem, they need to be replaced.

  • xXmatt69Xx1 Level 1 (60 points)
    Nope... not the problem. I unscrewed the three screws on the bottom of the iMac and i took the back case off and i checked the capacitors. None of them have brown leaking from them and all of them are flat. I just cant get my finger on the problem. I guess i'll have to bring it to an Apple Store or something
  • arnie Level 5 (4,065 points)
    as a guess, your hard drive maybe failing, see if you can boot from the OS disc and run the drive test
  • jeffreystern Level 1 (0 points)
    Having the same problem with a friend's G5. She said she had installed iWork 08 and right after that her iMac started operating very slowly. I had her start up in Safe mode and that worked for a day, but now I can't even get it to start in safe mode. it also won't boot from any disk, Leopard disk, DiskWarrior, or original G5 disks. Have hooked it to one of my old iMacs through firewire (target disk mode) and can access the hard drive just fine. Ran DiskWarrior and used Drive Genius to repair permissions, but still no go. Also started in single user mode and ran fsck -y a couple of times until it said everything was fine, but still can only get to the blue screen. (note also deleted and removed all parts of iWork 08).

    Her iMac was one of the ones that had the logic board problems and she had a replacement board put in about 1 year ago. Could this be a logic board issue again? is there anyway to test for this remotely (as in through target disk mode since I can't seem to get into it any other way).


  • xXmatt69Xx1 Level 1 (60 points)
    When I Try to boot from a disc, the iMac freezes.
  • arnie Level 5 (4,065 points)
    if it freezes when booting from the install disc, it's likely a hardware problem since any software on the computer is bypassed.

    could be different things - RAM, hard drive, possibly the logic board.

    at this point it probably needs to be opened up to examine the logic board or maybe swap the hard drive to test.

    if it's a hard drive, the fix is not so bad, failed logic board is not worthwhile replacing.
  • xXmatt69Xx1 Level 1 (60 points)
    Logic Boards are very much too expensive. I would be better off buying a new iMac. Thank you for your help! You have very good answers! I don't know what I could of possibly done. I guess she was just an old G5 anyway. PowerPC's always get Kernel Panics, Logic Board Failures, etc. They are very old, you just can't blame the iMac. Anyway, I just bought an iMac 17" Intel Core 2 Duo 1.83GHz iSight Camera 512MB SD DDR RAM but... FOR PARTS OR REPAIR! I don't mind repairing things, I actually think It's kind of fun. When It comes, I'll probably need your help for this one. The seller said It would turn on with a question mark folder (WHICH CAN MEAN MANY DIFFERENT THINGS). But like I said In one of my posts, I'm only 14 years old so... all I want Is an Intel Mac. PowerPC was starting to **** me off. Every application nowadays Is Intel required anyways. Like all the graphics apps I never got to use on my iMac G5 that I like FOR INSTANCE: Cinema 4D, Adobe Photoshop CS5, Adobe After Effects CS5, SOny Vegas 9 Pro. They were all Intel required. I just hope I can fix this iMac thats shipping. I will really need your help soon!
  • arnie Level 5 (4,065 points)
    thanks for the update, keep in mind that the voltages can be dangerous around power supply area, if you decide to disassemble iMac.
  • xXmatt69Xx1 Level 1 (60 points)

    Yeah, and the seller said that the iMac wouldn't even boot from an external hard drive so I'm worried that It's a Logic Board failure. Well, we'll just have to wait and see. Hopefully It is a hard drive or software problem and I didn't buy It for no reason! I can easily replace the hard drive.

  • prosurfer93 Level 1 (0 points)

    matt try jholding the opt key on start up till it goes to a screen that will show a hardrive i a square wait for the square to finish loading then click it to boot into os x it might work i have a g5 and have had the same problem and this works every time

  • xXmatt69Xx1 Level 1 (60 points)

    Thank's for the post I'll try this when the iMac Is shipped here i have read on some forums that this is usually caused by the iMac forgetting where to boot from so you need to remind it by doing this. Hopefully It works!