What was found
MAIN CARGO DOOR MSG ON AT 12000 FT, OUT AT 7000 FT & IN DESCENT. ACCOMPLISHED FIM 52-7 FT 809, VERIFIED SWITCH S9023 OUT OF ADJUSTMENT, ADJUSTED CARGO DOOR LOCK INDICATOR SWITCH S9023. ACCOMPLISHED MAIN CARGO WARNING SYS TEST IAW AMM 52-71-09. ACFT PRESSURIZED ON GND WITH APU SOURCE, AMM 21-31-00, MAIN CARGO DOOR WARNING LIGHT NOT DISPLAYED AT THIS TIME, CHECKED NORMAL, DID NOT DUPLICATE. MDDR REMAINS OPEN, FLIGHT CREW EVALUATION REQUIRED.