corrupted tty(3 to 7) and recreating them with mknod

Hi, (distro Red Hat 7.2) ttys 3 to 7 got corrupted, mingetty is unable to initialize them and I can chmod, chgrp nor chown them... neither remove them!! How can I get rid of them and rebuild them using mknod? Anybody had this kind of problem before?? Thanks alot!! Raul