I think I figured out the issue.  For some reason, I cannot keep serial cable plugged into them for a extended amount of time.  I unplugged them and the issue has not come back for two weeks now.
Hi I am running two N3024 with firmware 6.5.1.3, not stacked.  I have been having a issue with these switches reporting false fan and power supply alerts after 1-2 days of a reboot.  They run fine after the reboot and then the trapmgr messages start appearing.  I also see a message stating "warn insert_optics: optics sfp inserted in Gi1/0/23.  I don't have any SFP modules. Any help or suggestions would be helpful.   Thanks
N3024 fan and power supply issues