In my particular case I had a CentOS box that ran without X server and experienced some obscure, intermittent lockups. So, I needed to hook up the display, hoping to see some output like kernel call trace or maybe some error messages the box locks up the next time. The problem was that the system would dim the screen and when the box locked up I couldn’t see anything that might had been printed on stdout.
After quite a prolonged session of error and trial, what I learned was that simply issuing setterm -blank 0 in a terminal over ssh session (didn’t try to directly enter this command, let me know if this works for you) wasn’t working. So, what I ended up doing was adding
% echo “/usr/bin/setterm -blank 0” >> /etc/rc.local
to the end of /etc/rc.local and rebooting the box.
That did it for me (finally! lol)