As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT DEPARTURE, EICAS MSG APPEARED, CREW REST LOWER CH2 SMOKE DETECTOR. REMAINING CH1 OPS OK--AND BOTH AFT CARGO COMP SMOKE DETECTORS OPERATE NORMALLY. REINSTALLED ORIGINAL SMOKE DETECTOR IN FWD CARGO PIT. REPLACED AFT CARGO SMOKE DETECTOR. GROUND SYSTEM TEST PASSED. NO EICAS MSG'S. OK FOR SERVICE