I have a strange problem that suddenly cropped up on my laptop. It
just completely shuts down with no warning whatsoever. It definitely
isn't a software thing, because sometimes it will do it before it even
does the POST. At times when I am typing in the BIOS password, it
will shut down. Sometimes it turns completely off, and other times
the screen goes black and there seems to be no response, but the
lights for the wireless network and other backlights are on.

I thought it might be a temperature problem, but I'm not so sure now.
I took the thing apart and cleaned out some lint from the heatsink,
but when I put it together and booted it, it shut down when the O/S
was just starting to load. The computer had been off for a good hour
or more while I cleaned out the lint and should have been cool.

It shut down repeatedly on trying to boot it after that, but then I
flexed it and beat on it a bit and it booted up fully. It stayed
booted for a couple hours while I worked on some things, but then shut
down again.

I'm suspecting an intermittent short somewhere, but I was hoping maybe
someone had a similar experience and knows where to look or what to
replace.... perhaps the whole laptop

Oh, it's a 1.4Ghz Celeron if that makes any difference.

Thanks,
Dave