What was found
AIRCRAFT RETURNED TO PLATFORM AS A CONSEQUENCE OF VHF NR 1 FAILED. DURING MAINTENANCE REVISION, IT WAS DETECTED THAT WHEN CAPTAIN AUDIO BOX WAS USED, THE FIRST OFFICER AUDIO WAS BLOQUED. AIRCRAFT WAS SENT TO THE HANGAR, THE CAPTAIN MICROPHONE JACK WAS CHECKED AND LINE RZ32J24 WAS DETECTED WITH CHAFING. THE LINE WAS REPAIRED AND MICROPHONE WAS REPLACED IAW MM 20-50-00 AND 23-50-02, RESPECTIVELY, TESTED CORRECT.