What was found
TECH SUPPORT UPDATE ON A LEVEL 2 CHRONIC NGS DEGRADED WITH A 28 FAULT OCURRING ON THE GROUND SUSPECT THE LEFT PACK FLOW CONTROL AND S/O VLV PLZ PERF FIM TASK 47-30-T802 STEP F IF NGS HEAT EXCHANGER AND LEFT RAM AIR DEFLECTOR DOOR ARE OK PLZ REPLACE VLV THX. CARRIED BY ELB PER FIM 47-30 TASK 802 REMOVED AND REPLACED PACK FLOW CONTROL AN D SHUTOFF VALVE, IRW 737 AMM 21-51-01 ALSO CHECKED SECONDARY CHE CK VALVE FOR PRESENCE OF FUEL OR FUEL SMELL AND FOUND NONE. SYST EM OPS CHECKS GOOD AND NGS GREEN LIGHT PRESENT