Kate-Tron

Q: PowerBook 5300- Grey screen, no response

Recently came across a PowerBook 5300cs. Cosmetic condition is good, when I turn it on I get the boot chime and disk activity- but just a blank grey screen. No Happy Mac, no Sad Mac, no Disk Error, just grey. Wiggling the screen around doesn't cause any artifacting so if the video ribbon cable is either fine or really gone. I do have a Color Plus 14 display, but I can't find the adapter I had at one point to connect wide DB-15 to the bizarre PowerBook video connector.

 

Any ideas? I'm handy with fixing electronics, so if a potential fix would involve difficult soldering or even reflowing joints (was BGA even a thing in 1995?) I can handle that.

PowerBook, Mac OS 8.6 or Earlier, PowerBook 5300cs

Posted on Jul 29, 2015 10:47 PM

Close

Q: PowerBook 5300- Grey screen, no response

  • All replies
  • Helpful answers

  • by Jan Hedlund,

    Jan Hedlund Jan Hedlund Jul 30, 2015 2:43 AM in response to Kate-Tron
    Level 6 (9,901 points)
    Jul 30, 2015 2:43 AM in response to Kate-Tron

    Any difference if you squeeze at various places on or around the display? Can anything at all be seen on the screen if an external light source is used? It is of course extremely difficult to locate the fault without having opened the computer (guides at ifixit.com may be of help) and without access to another PowerBook 5300 (that would allow you to swap parts for tests).

     

    In principle, with proper pinout knowledge, it should be possible to solder leads from the computer's video port to a DB-15 Mac (or a three-row VGA) connector, but that is a lot more work than trying to find the PowerBook video adapter cable.

     

    See also PowerBook 5300cs blank screen.

  • by Kate-Tron,

    Kate-Tron Kate-Tron Jul 30, 2015 9:29 PM in response to Jan Hedlund
    Level 1 (0 points)
    Jul 30, 2015 9:29 PM in response to Jan Hedlund

    Shining a light at the screen doesn't reveal anything. The backlight is working, just a bit dim due to age. No changes if I squeeze around the display; it gets brighter or dimmer if I twist it- but that's just polarization I think.

     

    Tried the PROM and PMU reset, no changes.

     

    I'm fairly certain the machine actually is working properly other than the internal display not showing an image- if I type M for "Macintosh HD" and press RETURN, I can hear disk activity like it's opening a directory, and if I press the power button and hit RETURN, the machine powers off as would be expected by doing that under System 7.

     

    I can't find the adapter cable to try it on my CRT. Tonight I may pop the case open on the PowerBook and see if there are any obvious loose connections or damaged cables.

  • by Kate-Tron,

    Kate-Tron Kate-Tron Aug 2, 2015 10:46 PM in response to Kate-Tron
    Level 1 (0 points)
    Aug 2, 2015 10:46 PM in response to Kate-Tron

    Further update-

     

    I disassembled the 5300 tonight and re-seated connectors

    -Video card

    -Internal display (both on the logic board and inside the panel)

    -PMU

    -RAM

    -HDD

     

    No change. I also tried with and without the optional video card, no change. With the case open I can really hear the hard drive going- it's definitely booting the OS so this is a "cannot get video signal to internal panel" issue and not a "logic board is totally borked and computer is not booting" issue.

     

    I found an inexpensive source for the video adapter cables, I'll try that while silently cursing Apple's obsession with using proprietary ports and dongles for video output.