What was found
COULD NOT TRANSMIT ON EITHER SATCOM 1 OR 2, MULTIPLE ATTEMPTS WERE MADE ON SATCOMS 1 & 2 USING BOTH CAPTAIN`S AND FIRST OFFICER`S AUDIO CONTROL PANELS, HF/SAT TRANSFER SWITCH WAS PROPERLY SET TO SAT. ATTEMPTS INCLUDED USE OF HEADSETS, AUDIO PANEL, RT SWITCHES, YOKE MIC BUTTON, AND CAPTAIN`S HAND MIC. ON EACH ATTEMPT CALL COMPLETED AND DISPATCH WAS RECEIVED LOUD AND CLEAR. THERE WAS A SIDE TONE WHEN TRANSMITING BUT DISPATCH WAS NOT RECEIVING AUDIO. ACFT GROUNDED. PERFORMED GROUND VERIFICATION ON SAT 1 & 2 IAW AMM 23-15-00-730-801. VOICE TEST SUCCESSFUL FOR BOTH OUTGOING AND INCOMING CALLS.