Hi Cam: First of all relax, then verify into a dummy load that the 720A is OK. If OK, then verify that the amp input relay and circuit is OK .Does the 720A work OK through the amp? That is with the amp in standby , do you get 100W RF output into a dummy load at the output connector of the amp? You need to take it step by step. Good Luck, Larry K4LXV.