What was found
FAINT ODOR LIKE BURNING RUBBER ON F/O'S SIDE ONLY, INTERMITTENT. NO SIGNS OF ANY OVERHEATING. PER CREW, NOT AN ELECTRICAL ODOR. RAN PACKS BOTH HOT AND COLD, OPERATED FOOT AND SHOULDER HEATERS, PERFORMED ENGINE RUNS AND SUPPLIED PACKS WITH ENGINE AIR, APU AIR. NO DISCERNIBLE ODOR DETECTED. INSPECTED FWD E & E AREA, INSPECTED LIGHTS IN COCKPIT, NO DEFECTS NOTED.