What was found
OIL ODOR IN CABIN. F/A THINKS IT COULD BE ASSOCIATED WITH OVERHEAD LIGHTS. OIL ODOR FROM APU, RAN ENGS NO ODOR. APU BLEED INOPERATIVE, APU USEABLE FOR ELEC. OPERATED ALL OVERHEAD LIGHTS IN FWD & AFT GALLEYS, AND CABIN CEILING LIGHTS AT MAX BRIGHT. (GROUND EXTERNAL POWER USED). NO ELECTRICAL ODOR NOTED THRUOUT ACFT. ACCOMPLISHED PACK BURNOUT PER MM, ISOLATED ENG BLEED HP AND IP VALVES AND APU. SLIGHT ODOR ORIGINALLY FROM APU, PACK BURNOUT ACCOMPLISHED NO ODOR NOTED. APU BLEED DUCT CLEAN, NO OIL FOUND.