What was found
AFTER STARING APU AND BRINGING PACKS ON-LINE THE SMELL OF DIRTY SOCKS PERMINATES THE CABIN. GROUNDED - YES. PERFORMED CONDITIONAL INSP REF AMM 05-51-56 SMOKE FUMES IN CABIN PERFORMED ENG RUN REF FIM 21-00 TASK 806 IDENTIFIED FUMES WITH APU BLEED ON L PACK ON RIGHT PACK OFF. NO NOTICEABLE FUMES IN ALL OTHER CONFIGURATIONS. ODOR IS LEVEL 1. SWABBED APU LOAD COMPRESSOR CASE FOUND EVIDENCE OF OIL CONTAMINATION. REMOVED AND REPLACED APU AMM 49-11-00/401.