What was found
DIRTY SOCK OR BURNING OIL ODOR NOTICED BY ALL CREW MEMEBERS WHEN BOARDING THE ACFT. ODOR NOTICED IN COCKPIT AND ENTIRE CABIN. BLEED CONFIGURATION, APU BLEED ON, NR 2 PACK ON, NR 1 PACK OFF. PERFORMED TSM 05-50-00-810-831-A. CAUSE INDICATED TO BE APU AND PERFORMED ENGINE RUN. ODOR ONLY PRESENT WITH APU RUNNING.