"DaveC" wrote in message
news.net...
Mac PowerBook G4 won't boot (but will give the boot "bong"). If I press on
the case below the motherboard, it boots and, if pressure is maintained,
functions normally.

If pressure is released, video will scramble, and -- sometimes -- system
will
freeze.

I've run the mboard out of the case with just power, and pressed,
squeezed,etc. without any hint of what I'm looking for. I've examined it
with
a glass looking for cracked board and/or traces, separating solder joints,
the obvious. It does still fail out of the case, so this isn't a
short-to-case issue.

Any ideas what else this might be? Do ASICS and other ICs fail
(internally)
in this mode?



It's gotta be a trace, solder joint, or via. Try resoldering anything in the
area, if that doesn't work and it's otherwise garbage, you could try heating
up that area of the board with a heat gun until it's hot enough to melt
solder then let it cool off.