13 Jul
2006
13 Jul
'06
4:31 p.m.
Jules Richardson wrote:
The logic board *looks* healthy enough - it seems to
have escaped the
corrosion that's got bits of the case.
Right, the machine seems (surprise!) rather dead. I've got 5.05V on three of
the regulators, but 'only' 4.95V on the second-from-front one; I'm presuming
that's not a problem, though (are these things wired in parallel, or do they
feed individual bits of circuitry? I dragged the schematics off the 'net, but
they don't make the power distribution clear)
What's the LED for? It's not lit on this machine when power's applied - is it
supposed to be, or does it signal some other activity and spends most of its
time unlit?
The RAM chips seem to be running at a level best described as "fairly warm".
Not too hot to touch or anything, but they're still putting out a fair bit of
heat - but then given the age/technology maybe that's normal? (certainly there
don't seem to be any that are running any hotter than the rest)
I'll put a 'scope on the video lines in a mo and see if it looks like it's
even generating plausible video signals...
cheers
Jules