As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UPON TURNING ON BATTERY MASTER SWITCH, INSTANTLY SMELLED BURNING ELECTRICAL. SHUT OFF AIRCRAFT. (FLT 6228) FOUND BURNING SMELL EMANATING FROM PA/INTERPHONE CONTROLLER AMP. REPLACED PASSENGER ADDRESS AMP IAW AMM. BURNING SMELL CEASED. PN: 5582-1-1 SN ON: 315 SN OFF: 162.