M> Today I wanted to test something, and couldn't get it to power up. No light,
M> no fan or disk drive start spinning. Nothing. I checked the connectors,

Have you tried to push cuda reset button ?
It should found next to the memories and SCSI cable connecter
on the mother board.

 I did have another occasion that did not fix the problem by
this button. But removing batterry, removing Power Cables, and leave
several hours, it powers up again.  The battery does not matters
in that case. It just did not remember the date, real-base if
the Power cables plugged off.
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Makoto Fujiwara, 
Chiba, Japan, Narita Airport and Disneyland prefecture.