What was found
RECEIVED A CABIN PRESSURE WARNING WHILE CLIMBING THROUGH 10,000 FT. NO DECOMPRESSION. UNABLE TO PRESSURIZE IN MANUAL MODE. RETURNED TO FIELD, LANDING UNEVENTFUL. VERIFIED MCD SEAL AND CARGO DOOR SEAL OPERATION, CLEANED 18 PSI SYSTEM LINES WITH NITROGEN, REPLACED SYSTEM DESSICANT SILICA FILTER, COMPLIED WITH OPS TEST OF PRESSURE CONTROLLER, IAW AMM 21-31-06-700-001. COMPLIED WITH OPS TEST OF PRESSURE CONTROLLER IAW AMM 21-31-06-700-001. COMPLIED WITH PRESSURIZATION TEST IAW AMM 21-31-00-720-801, CHECKED GOOD, NO CDS CODES FOUND FOR CPC, SYSTEM TESTED GOOD. RETURNED TO SERVICE.