Just a guess here but the
RF is causing it to go into overvoltage protection mode and shut down.  If 
metered it will show 0 volts and 0 amps when in this mode.

In my case it was an Astron on a mountain top running a repeater.  Replaced 
it with a Samlex supply and it has been running about 2 years now with no 
issues.  I also know of other repeater owners running these supplies for as 
long as 10 years with the same supply.

73 de Brian, k5in