What was found
DURING INITIAL POWER REDUCTION AT TOP OF DESCENT, A SULFUR BURNING ODOR WAS PRESENT FOR ABOUT 30 SECONDS. NO SMOKE OBSERVED & ODOR QUICKLY DISSIPATED. INSPECTED ACM INLETS & OUTLETS FOR OIL, NONE PRESENT. INSPECTED APU INLET & EXHAUST FOR OIL, NONE PRESENT. R & R THE COALESCE SOCKS. PERFORMED DUCT BURN OUT IAW TASK CARD TC-750-21-120801M R1. OPS & LEAK CHECKED GOOD. NO ODOR PRESENT, RAN BOTH ENGINES, SHUTDOWN APU, RAN BOTH PACKS IN MANUAL & AUTO MODE AT FULL HOT TO COLD AT DIFFERENT POWER SETTINGS, NO DEFECTS NOTED.