learcoa
Level 1 (0 points)

Q: PPC Imac G5 - Ramdomly black screen with background running

Hi : )

I decided to write on the forum because I need some help with the only computer at home with 2 users.

 

Yesterday the computer when black screen when running, without coming back to normal. I shut down and tried several times to turn it on, but all sounds good, like had load perfectly, except the screen was black all the time. I do a lot of research today looking for clues to the ramdomly black screen. I had always used my brightness at the minimum.  I check for capacitors, all seem perfect. The only thing that work to bring up the display again was doing the resets of power cord and Open terminal, then suddenly when it finished loading the display showed up the desktop. So here am I, now looking to solve the problem completely, because ramdomly it goes to a black screen for 1 or 3 sec.

 

That afternoon  I noticed a few changes in voltage, one of them was 10-12sec. The computer was running and the printer too. Them the printer began to go on and of like crazy. I fixed it unplugging the power from the printer and wait a few minutes. Then like 6-8 hours later the computer when black screen. I dont have a ups battery.

 

Any info, clues or tips, will be appreciated,

 

Thanks in advance,

 

Omar

iMac, Mac OS X (10.5.8), Imac G5 PPC 17" 2.0ghz 2gb ram

Posted on Feb 9, 2014 6:10 PM

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learcoa

Q: PPC Imac G5 - Ramdomly black screen with background running

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  • by rccharles,

    rccharles rccharles Feb 11, 2014 11:00 AM in response to learcoa
    Level 6 (8,476 points)
    Classic Mac OS
    Feb 11, 2014 11:00 AM in response to learcoa

    You may have a problem with the video chip.

     

    Here is how to tell...

       Shutdown your machine.  Hold down the shift key.  Poweron.  Bootup will be longer.

         Wait awhile while you harddrive is being checked.

       An article on how to boot into safe mode.

         http://support.apple.com/kb/ht1455

     

    Runs OK in safe mode...

    Running in Safe mode leaves out some video drivers.  Which results in your machine not using advanced video hardware. As luck would have it, you can run the safe mode video drivers in normal mode. 

     

    Here is how:

    https://discussions.apple.com/message/16057567#16057567

     

    Look through the above thread.  See the second page.  You don't have to read through the first page.  Just go to the part where I try a solution that works.

     

    Using the safe mode video driver results in these limitiations:

       -- OpenGL acceleration is not supported on this mac

       -- Your mac lacks quartz extreme acceleration

     

    Summary of G5 problems. Includes instructions on a hardware fix for the brave at heart:

    See -Rotten Apple- articles in both of these threads.

    https://discussions.apple.com/thread/4023152?tstart=0

    https://discussions.apple.com/message/18700825#18700825

     

    Robert

  • by girlsonboard,

    girlsonboard girlsonboard Feb 11, 2014 4:14 PM in response to learcoa
    Level 1 (0 points)
    Feb 11, 2014 4:14 PM in response to learcoa

    Since these threads aren't merged, I'm posting the same in several threads.

     

    I've had the screen blank problem, took the IMac in twice, got home, still not fixed.

     

    But they used their own keyboard in the shop and couldn't reproduce the problem. I switched keyboards and so far so good. It's been 3 days now.

     

    I'll keep folks updated. Don't get a new graphics card before you try a new keyboard.

     

    Be sure to take the batteries out of your keyboard when testing another one as the board does not turn off if it is like mine.