[Ti] Diagnostic assist for Titanium PowerBook needed

[Kynan Shook]

My first guess would be that the display cable is pinched, of course,  
although I've never seen that affect the external display too.  But,  
before you replace the logic board, I'd suggest unplugging the LVDS  
cable to the display.  That's the one that carries the video signal  
(but not the power for the backlight).  It has a ton of very thin  
wires, and, IIRC, runs through the left hinge.  Some of the power  
cables might have shorted, for example, which might cause it to not  
boot.  It's not hard to get to; just take off the bottom cover and  
you should see it.  While you have it open, you could also try  
unplugging the inverter cable (two wires, generally pink and white)  
that runs through the other hinge, but it's not as easy to get to -  
you'd probably have to take out the whole logic board.

Anyway, if you still have problems getting it to boot with an  
external display connected, then I'd say the logic board is a safe  
bet.  Otherwise (or with no testing at all), I'd probably put my  
money on the display itself - which generally goes for a lot more  
than $150.


Kynan Shook
kashook at wisc.edu
http://homepage.mac.com/kynan/


Dennis Fazio <dfz at mac.com> writes:
> I have a broken 5 year old TiBook (667MHz, 1GB, 60GB) and could use
> some assist in diagnosing before I decide what to do next:
>
> Here's the details:
> The screen was flashing intermitantly as if the wiring to the display
> was faulty. Upon close examination, I found that the hinge was broken
> on one side and the screen corner was beginning to separate. I did
> some surgery and was able to loosen the hinge pivot and glue things
> back together so that though the hinge it doesn't provide any
> friction hold for the display, it does hold the screen to the base
> and pivots just fine. Friction hold is done by the other undamaged
> hinge.
>
> I noticed no wiring damage, and wiggling the wires during a mid-
> repair bootup check showed no display problems.
>
> After the glue dried, powerup resulted in about a 10 pixel scrambled
> line across the bottom of the display. Touching the machine in
> various ways intermittantly made the display scramble and the machine
> had to be restarted to make it useable again. Over time, the machine
> has deteriorated worse so that now, not only is the display dead, but
> the machine won't boot up.
>
> I have:
> reset PMU
> reset PRAM
> pulled memory boards one at a time
>
> I attached an external display, and when the LCD flipped out, so did
> the external display.
>
> Now fiddling around, jiggling or touching might get it to boot once
> in twenty tries. I can log in after booted, but after a while it
> freezes with a jumbled display.
>
> I'm thinking the logic board is in its final death throes and am
> willing to replace it for $100-$150 to get the machine back.
>
> However, before investing, I'd like some confirmation that others
> think this is likely the problem or could it be something else?
>
> Memory and disk seem fine. Is there a power controller or something
> that might be the cause? Any ideas or benefits from your experience
> appreciated.