What was found
A DIRTY SOCK SMELL WAS DETECTED AFTER STARTUP UNTIL TOC. PERFORMED AMM 21-00-21-302-030, REMOVAL OF OIL CONTAMINATION FROM AIR CONDITIONING AND PNEUMATIC SYSTEMS. DURING ENGINE RUN, AFTER SELECTING R PACK TO ON, NOTICED FAINT ODOR COMING FROM GASPER VENTS. PERFORMED CHECK, FOUND AND REMOVED DEBRIS INSIDE RT PRIMARY HEAT EXCHANGER. OPS TEST RT PACK IAW AMM 21-51-00, NO FURTHER DEFECTS NOTED AT THIS TIME.