The AM transmitter will be muted with no RF output. The AM 500A and 1A transmitters only have one power supply; most likely it will need to be repaired/replaced. The AM 2.5E, AM 5E, AM 6A, and AM 10A transmitters have multiple power supplies. However, the 120Hz is only supplied by Power Supply #1. You can swap Power Supply #1 with one of the other supplies and get the transmitter back on the air at a reduced power.