As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED A BURNING ODOR IN THE CABIN AND FLIGHT DECK WHEN CABIN INTERPHONE SELECTED. MX PERFORMED OPS TEST OF PASSENGER ADDRESS & CABIN INTERPHONE SYS WITH NO DEFECTS NOTED, PERFORMED GVI OF BOTH LT AND RT POWER DISTRIBUTION BOXES WITH NO DEFECTS NOTED, UNABLE TO DUPLICATE THE DISCREPANCY AND THE ACFT WAS APPROVED FOR RETURN TO SERVICE.