As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED. THE SMELL OF SOMETHING BURNING PERSISTED FOR A FEW MINUTES. HEARD A FAN BENEATH US STOP. VERIFIED AIR CONDITIONING INLET VALVE IS OPEN PER AMM 21-26-00 AS REQUIRED. REPLACED EXTRACT FAN (18HQ)PER AMM 21-26-401 CLEARED MEL 04-1114DC-C.