Best way to troubleshoot intermittant lockups on F12

[Mark Goldberg]

I have an F12 installation that experiences intermittent lockups,
usually at times of heavy usage.
The system just locks up solid, keyboard and mouse are non responsive.
Graphical screen remains
the same as it was when it locked up. Nothing is recorded in the
system logs, and I also have
logging to a remote machine and nothing is sent to there either. If
you attempt to telnet in, you get
the first telnet message with the kernel name but no login prompt and
it times out. Only a hard reset
and reboot gets it back.

I've extensively tested the hard disks and memory. Processor temp is
well controlled by a big
fan.

This is on an ASUS M4A77D motherboard (AMD 770) with an AMD 9850
processor. I've tried pci=nomsi
and it does not seem to change things.

Twice, running yum caused the lockup, but any intensive progam can. It
reencodes video early
in the morning and has locked up three times then.

Any suggestions would be appreciated.

Mark