Power off

[Tyler Larson]

I ran into a problem (bug?) that I would like to help solve, but I'm at 
a loss as to where to go next. My laptop (Dell C400) used to run Linux 
just fine, dual boot with Windows. In the past few months, I've 
installed XP SP2 on the Windows side, reinstalled Windows a few times 
(it happens), and updated by BIOS image. I somehow managed to trash my 
partition table attempting to put GRUB back as my bootloader, then had 
to reinstall everything all over again (windows and Linux). I've since 
downgraded the BIOS to the previous known-good version to try and fix 
the thing. Windows works fine, but on the Linux side....

The computer powers itself off without warning--no matter what is, or 
isn't, running. Certain things seem to trigger it, and it may be tied to 
high CPU load. I can trigger the shutdown fairly reliably by running 
aircrack on a packet capture file. To rule out any background services 
as being the culprit, I booted with init=/bin/bash, ran aircrack, and 
sure enough, it  powered off after about 90 seconds. This behavior has 
continued no matter what kernel I use--I'ved tried with both the 
original FC3 kernel and the most recent one. In fact, the machine 
powered itself down a number of times while I was running off the 
install CD. It took 10 tries before I got it to complete the install 
process.

So, my question to you all is--how can I possibly get some useful 
information to start diagnosing this problem? There's nothing in the 
logs on disk, of course. There's no warning, no panic, no nothing. Just 
a quick *plink* and it's gone.