Hi
If no other cables are connected the RRC is protected with a littlefuse (automatic reset) but if a radio is connected both to the RRC and to the same Powersupply then things can happen. Most common is that the common mode fiter L2 just behind the DC connecter is burned, It's easy to measure and it can be replaced by jumpers. Sometimes some of the EMI fiter between the jumper socket and the RJ45 connector on the front get burned, they can also be replaced by a jumper.
73 de mike