Batboard

I've got a VHF 350 watt Quantro repeater that the customer found popping its electrical breaker(after 4 years in service). I checked both power supplies and both the low power amp and the High Power amp in sequence (in the shop) and the station is up and running like a champ. Could this be due to the thermal circuit breaker in T651? Any other thoughts? Thanks in advance for your help.

Toby Kiuntke
KC0FRU