As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DIVERTED, DUE TO SMOKE DEVELOPED, LOOKED LIKE ORIGINATING FROM MAIN CARGO DECK. COULD NOT DUPLICATE SMOKE ON THE GROUND. DEFERRED NR 2 AIR CONDITIONING PACK AS MOST PROBABLE CAUSE. REPLACED COALESCER BAG IN ALL 3 AIR CONDITIONING SYSTEMS.