I turned off my Ubuntu box earlier today and when I turned it back on 
nothing appeared on the screen(s).  I can't log into it from the console 
or by ssh and I can't ping it.  I hear the fan, and it seems to be louder 
than it used to be.  Do you think it's the power supply?  What should I be 
doing to figure it out?  Maybe the mobo went out.

Mike