What was found
AFTER TAKEOFF, THE CREW PERFORMED A PACKS OFF TAKEOFF, THE AIR CONDITIONING PACKS WOULD NOT TURN ON AND THE ACFT WOULD NOT PRESSURIZE. THE CREW RETURNED TO DEPARTURE WITHOUT FURTHER INCIDENT. MX ACCOMPLISHED FIM PROCEDURES 21-31-00, FIG 104 AND BIT STEPS 1, 2, 22, 23A, 24, 25, 26 AND 46. TEST CHECKED GOOD IAW FIM 21-31-00 FIGURE 103. ACFT WAS RETURNED TO SERVICE.