As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING CABIN CHECK BY INFLIGHT SERVICES BOTH LAVATORY SMOKE DETECTORS WERE FOUND ACTIVATED AND SMOKE IN CABIN. LEFT HAND HEAT EXCHANGER FAN FOUND INOPERATIVE. EXCHANGER FAN REPLACED AND EXCHANGER RAM AIR EXHAUST CONTROL VALVE (P/N 20211362) REPLACED