There are two things you need to do here.
1) make sure that there is a static IP assigned to the NIC card via /etc/sysconfig/network-scripts/ifcfg-ethx. dhcpd will refuse to run at bootup if this isn't configured correctly.
2) make sure that the dhcpd.conf file is correctly formatted. dhcpd will not run if this is incorrectly configured. make a backup of the dhcpd.conf file and replace it with a simple one that is sure to work.
mv /etc/dhcpd.conf /etc/dhcpd.conf.backup