What was found
DIRTY SOCK SMELL ON TAXI OUT .STARTED IN FLT DECK AND CONTINUED THROUGH CABIN.PACKS ON ENGINES.TURNED LEFT PACK OFF AND SMELL DISAPPEARED FOR 1-2 MINUTES BUT SHORTLY RETURNED.SWITCHED TO APU BLEED ON TAXI BACK TO THE GATE AND SMELL REMAINED. PERFORMED T/S OF SMELL OF SMOKE OR FUMES PER AMDS WORK CARD 0550 -2001,0550-2002,055-2003 AND 0550-6001.C/W NO GO ODI STEP1 T/S , STEP 2 LOCATING THE SOURCE, STEP 3 ELIMINATION OF THE SOURCE STEP 4 NOTIFY MCC AND STEP 5.REFER LOG #7218576 FOR FURTHER ACTION.A/C OK FOR CONT. SVC. (LP# 7218574)