[dba-Tech] Another Puzzle - computer doesn't boot all the way

Hello Friends,

Well, since we've solved the puzzle for the Fields-Family computer, I 
can get back to one I was working on earlier.

The patient is an IBM NetVista computer.  I have a family member with 
access to a sort of electronics junkyard, where discarded items go, many 
of which are still quite usable, but may need a little updating, and 
most of which have been discarded simply to make room for newer 
equipment.  The NetVista computer came from that source.  The operating 
system is WinXP SP3 - I did the installation of the operating system - I 
set up the user accounts - I installed OpenOffice software - I installed 
Vipre -I was working on the updates for all the software and the OS, and 
all seemed to be fine until I got to one of the final updates and had to 
reboot the system, and it wouldn't reboot.

I don't have the same detailed notes on this that I make when I know I'm 
dealing with a puzzle - I thought this was working perfectly - so, the 
sequence of events is no longer clear.  However, the POST was wrong - 
rather than the single beep, there was a series of beeps (4 or 5 in a 
row).  Looking up what that might mean, I found what I thought was the 
most likely culprit - a failing power supply.  If it doesn't send a good 
power signal, the system won't boot.  So, I bought a nice new power 
supply - the precise model called for by the NetVista specs - and 
installed it.  Booted right up.  Yay!  I continued working on the full 
setup of this machine, and had it running for probably an hour when I 
got to another reboot - and it wouldn't.  Same exact symptom.  The power 
comes on, the initial screen is displayed, and nothing more happens at 
all.  I put the computer aside for a while, because I had other things 
to tend to.

A month later I came back to the sleuthing.  Could be the CR2032 
battery, after all, the machine is ancient.  So, I replaced that.  
Booted right up.  Yay!  Continue setting things up just the way I will 
want them for a student computer in my little classroom.  The system 
seems to be running just fine, until I reach another needed restart.  
Won't boot.  Same exact symptom.  Power on, initial screen is displayed, 
and nothing more happens at all, no matter how long I wait - waited five 
hours just to be sure.

So, I think there is a thermal issue here.  When the computer warms up, 
the reboot does not work.  If I let the sucker sit for a week, it'll 
probably boot for me again just fine. 

Now, one of the NetVistas I already had running reliably, has developed 
the same apparent symptom.  Reboot starts, but hangs at the display of 
the opening screen.

Have you seen this symptom?  Is it likely a thermal issue?  Does it 
sound like a failing solder joint?  Does it sound like a failing 
switch?  Any ideas?

Thanks,
T