15" PowerBook G4: no video

Discussion in 'PowerPC Macs' started by J.Appleseed, Sep 5, 2013.

  1. J.Appleseed macrumors regular

    J.Appleseed

    Joined:
    May 27, 2012
    Location:
    The Netherlands
    #1
    Hi all,

    I've been messing around with a 15" PowerBook G4 lately. It's the 1.33 GHz aluminum model, with a 40GB harddrive and 768MB of memory.

    When I got it a few days ago, it would succesfully boot ± 1 out of 2 times. It would continue to work properly for some time until the screen would slowly change to produce opaque white lines all over the display, causing the screen to be almost entirely white in the end.
    As soon as the white lines started to appear, the system would become unresponsive (i.e. moving the cursor wasn't possible, as if a screenshot was shown underneath all the white lines).
    However, if I would readjust the display/lid, the white lines would go away and the system went back to its original state, i.e. before the white lines. I could just continue working as if nothing happened.

    I also experienced the display to show three times the same screen, only moved horizontally (e.g. the boot-up screen would show :apple: :apple: :apple: instead of a single, centred :apple: and the three screens would over- and underlap each other. This behavior continued when it booted to the desktop.

    As of today, if I try to turn the computer on, I hear the harddrive starting to spin and the "chime" can be heard, but after that the boot process seems to stall. I don't think that the computer fully boots into the OS since the "volume up" button lights up the numlock-light instead of making the 'volume up/down sound. Also, I can confirm that it's not a backlight issue since there just aren't any graphical renderings on the display (I checked with a flashlight behind the Apple logo).
    Note that the numlock-button is situated next to the "volume up" button, and if I remember correctly it would indeed light up the numlock-button during the boot process; it would work correctly when the system was fully booted.

    My first guess was that the graphics card might be toast. However, when I discovered that readjusting the display/lid would (temporarily) 'solve' the issue, my guess was that the display data cable wasn't connected properly.
    Now, since it won't display anything at all, I think both options are possible.

    What do you guys think/advise?

    Having had about 5 PowerPC Macs, I know the platform is fairly limited nowadays but if possible, I'd like to make it functional again because it's still in nice condition otherwise. I'd either like to make it my secondary computer or use it to make my father familiar with Mac OS since he's always worked with Windows.
     
  2. rabidz7 macrumors 65816

    rabidz7

    Joined:
    Jun 24, 2012
    Location:
    Ohio
  3. J.Appleseed thread starter macrumors regular

    J.Appleseed

    Joined:
    May 27, 2012
    Location:
    The Netherlands
    #3
  4. eyoungren macrumors P6

    eyoungren

    Joined:
    Aug 31, 2011
    Location:
    Phoenix • 85037
    #4
    Ignore him. Don't feed the rabidz.

    Try hooking your Mac up to an external monitor. If it works then it means it's either the inverter, the cable or the display itself. Over time, the cable can fray because it runs through the hinges. If you get perfect video when hooked up to an external display then it's NOT the logicboard or the video chip. If you don't then, yeah, you'll need a new logicboard.

    Replacing the LVDS cable is a real PITA! You have to get the lid of the LCD detached and doing that is painstaking work. Some people can do it fine, but I made a mess of it way back when. Personally, I'd just find a new LCD on ebay. Search for one for your model and make sure that you get an LCD with bezel. Lots of companies out there trying to rip people off just for the LCD itself.

    I would suggest looking for Macs of your model that have been advertised as broken or not working. Usually, you can scavenge an LCD from those, or sometimes people just sell them outright. My 17" Powerbook G4 had the same symptoms a few years ago. After making a mess of replacing the LVDS cable I just replaced the entire screen. Cost me $80. In the long run doing that will just save you time and frustration.
     
  5. Goftrey macrumors 68000

    Goftrey

    Joined:
    May 20, 2011
    Location:
    Wales, UK
    #5
    [​IMG]

    And the quote of the year award goes to - eyoungren!
     
  6. J.Appleseed thread starter macrumors regular

    J.Appleseed

    Joined:
    May 27, 2012
    Location:
    The Netherlands
    #6
    Okay. Yeah, the external display (attached via DVI) didn't work either. I'll just cancel my LVDS order and order a logic board instead :)

    Thank you so much for your quick reply - I could've messed up a perfectly fine display! :eek:
     
  7. eyoungren macrumors P6

    eyoungren

    Joined:
    Aug 31, 2011
    Location:
    Phoenix • 85037
    #7
    You're welcome! Let us know if you need any help with the logicboard when you get it.
     
  8. J.Appleseed thread starter macrumors regular

    J.Appleseed

    Joined:
    May 27, 2012
    Location:
    The Netherlands
    #8
    Will do! Thanks so much for the kind advice :)

    It should be here in 2-3 business days, according to the webshop (US to Europe) so I'll keep you guys posted.
     
  9. California macrumors 68040

    California

    Joined:
    Aug 21, 2004
    #9
    Bump up your CPU speed to 1.67ghz (DDR1 ram version) if you are going to replace the logic board. Pretty sure they will swap out. Might as well have a speed bump.
     
  10. J.Appleseed thread starter macrumors regular

    J.Appleseed

    Joined:
    May 27, 2012
    Location:
    The Netherlands
    #10
    Too late, haha. Already swapped it with an identical 1.33 GHz logic board :)

    Working fine now, though. That's all that matters to me.
     

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