[CentOS] Yum update gone bad...

Morning list!

I have a situation that was brought about by a system crash during a yum
update.  The motherboard suffered a catastrophic failure due to busted
CAPS.  Lucky for me (or so I thought at the time), I had a spare,
identical motherboard as the one that failed.  I replaced the dud board
and rebooted.  This machine runs headless and is my primary
(personal/home) mail server.  I normally access the booting console via
hyper terminal when I need to change boot parameters or just watch the
system boot up!

Getting to the point, nothing comes up at all on the terminal screen.
So I hooked up a monitor and keyboard (even a mouse) to check what was
going on.  What I noticed immediately was that the kernel screen
selection screen did not appear!  Instead, I just got a message at the
bottom on the screen stating "Grub Loading Stage 2" or something to that
effect.  Straight from there, was the usual scrolling text up to the
point where SELinux starts.  Then nothing displays at all until the
final login screen.  Not even the "Nash" screen that prompts one to
enter "I" for interactive start-up appeared!

Could someone enlighten me on what I could check?  I have reinstalling
all packages that were installed just before and after the system crash
to no avail.

This is a system that was running CentOS 5.3 final and I was updating
several packages including upgrading the kernel from 2.6.18-128.1.6.el5
to 2.6.18-128.1.10.el5.

Cheers,
tkb.