DC switches stop passing all data

[JohnWall]

We have a remote repeater site with DC power. The switch just seems to shut off and I can't reach it or any of the devices connected to it. There are several APs, so there are multiple ways to join the network but none are working. I swapped it for another switch and after several months, it did the same thing. When I get on site, the switch is all lit up and the fix is a simple reboot. It has the latest firmware (currently 1.5.9rc1).

Any ideas?

John