[Ti] Diagnostic assist for Titanium PowerBook needed

[Dennis Fazio]

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.

--
Dennis Fazio
dfz at mac.com