20Mbps Backhull not booting?

we r running 20Mbps backhul units,
Device type 5.7GHz - BackHaul - Timing Master - 20 MBit
Software Version CANOPY 3.1.5 Sep 06 2002 13:31:09 BH20
FPGA Version 09110218

At one of our site, the power adopter is fine, the cat5 cable is fine but for no reason, the system wont come online…
After pulging it in for 5-8 hrs, it comes back online.

Any help will be much appreciated…

3.1.5 is a few years old so once the unit comes back up can you upgrade the code to the latest release and share the event log?