Redhat 8/9 & hardware troubles

[Ian Stephen]

Hi list

Been having trouble with IBM Aptiva Celeron 533 PC.  Was running Red Hat 
8.  Troubles seemed to get progressively worse.  Would work fine for a 
couple of days, then would have a crash, typically when shutting down.  
Would find that modules from XFree86 were missing.  Re-install XFree86 
and all it would be good again for a day or two.

Finally it wouldn't install rpms anymore, so tried to  upgrade to Red 
Hat 9.  Part way through got an error that said something was wrong with 
either the install media or my hardware.  Tested install media before 
and after, no errors.

Repartitioned and formatted the drive and did a new install of Red Hat 9.
Ran e2fsck -c (bad blocks) and got no errors.
Ran memtest86 for most of a day, 13 times through it's tests, and got no 
errors.

Now a couple of days later I find processes still running after I close 
apps in KDE.  Just crashed again when I logged off.

Don't think it's a heat problem as I haven't changed any hardware in a 
long time.  Box isn't dusty inside.

What tests might I do?  Maybe just change the mother board?  Power 
supply?  both?

Any suggestions welcome!

Ian Stephen