As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
VERY LOUD HIGH PITCHED HUM IN CAPTAIN'S & FIRST OFFICER'S INTERPHONE. FOUND CAPTAIN'S HAND MIC JACK AT ISSUE, CLEANED CONTACTS OPS OK. AUDIO SELECT SWITCH FOR FLT INTERPHONE LIGHT INOPERATIVE. REPLACED CAPTAIN'S AUDIO SELECTOR PANEL PER MM, OPS OKAY.