What was found
FLT #405 EWR-FLL. "ON DESCENT @ APPROX 10,000 FT ENGINES AT IDLE, APU OFF MAGIC MARKER ODOR IN FLIGHT DECK, DIMINISHED WITH PACK 1 OFF PER PROCEDURE RETURNED W/ PACK ON .;COMPLIED WITH INFORMATION NOTICE 2017-T015, STEP 1, ISOLATED FAULT TO TYPE 10 MISCELLANEOUS DUE TO ATOMOSPHERIC CONDITIONS PER TSM 05-50-00-810-085-B/TSM 05-50-00-810-085-D, ALSO CHECKED ENG AND APU OIL LEVELS, IN LIMITS, AND PERFORMED GVI OF APU AND FUSELAGE FOR LEAKS, NO LEAKS NOTED, AIRCRAFT OK FOR SERVICE .'