[tlug] Is it the hardware or the software killing my laptop?

[Dave M G <dave@example.com>]

TLUG,

I've got a nice little Panasonic "Let's Note" laptop, with Ubuntu Lucid 
installed. Has served me well for a couple years now.
Recently, it's been crashing. Sometimes it freezes and I have to reboot 
using the power switch. Sometimes X crashes, and I get taken to a black 
screen, where sometimes I can [ctrl]+[alt]+[backspace] and get to a 
login screen. Most times I have to force a reboot.
To make a long story short, I'm not sure if it's a software problem, or 
a hardware problem. Is it just kind of long in the tooth and starting to 
fail? Is it some new driver problem in Lucid?
The thing is, because it freezes and shuts down, it doesn't seem to 
leave much trace of what the problem was. It can't write out any logs 
after the problem, and I don't know if it can anticipate it. So I don't 
see any log or error messages. Not anywhere that I know to look, anyway.
I poked around /var/log, but I don't know what to look for. I didn't say 
anything in any of the logs that said "your computer crashed last time 
because ..."
Anyone have any suggestions as to what I might do to find the problem? 
I'd like to be sure what I'm dealing with before I consider replacing 
the laptop.
--
Dave M G