One of mine is acting up (an S3) and I've set it to reboot every 2 hours:
* 0,2,4,6,8,10,12,14,16,18,20,22 * * * /sbin/shutdown -reboot
Might be simpler as:
0 */2 * * * /sbin/shutdown -reboot
Thanks for the suggestion. Implemented. I freely admit to knowing just enough about crontab to be dangerous.