As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
1) AT BLOCK-IN IN SAN WHEN MAIN CARGO DECK SMOKE DETECTOR TURNED OFF, #2 SMOKE DETECTOR RED LIGHT ILLUMINATED . NO INDICATION OF SMOKE /FIRE VISIBLE TO CREW. LIGHT STAYS ON WEATHER SMOKE DETECTOR SELECTED ON OR OFF2) CLEANED #2 SMOKE DETECTOR LIGHT SOCKET IAW B-727 M/M 26-17-001.OPS CHECK GOOD.