What was found
#1 PACK OVLD AND #1 PACK VALVE FAIL IN FLIGHT CLIMBING THROUGH FL340. QRH PROCEDURE FOLLOWED.-C/A-FLIGHT CREW PLACARDED #1 PACK. MEL# 21-28 AUTH# 110034D-C MOC# 730088. CHANGED MEL 21-28 TO MEL 21-29 BOTH PACKS INOP AUTH 110034DM-C M PROCEDURES C/W AUTH 110034DM-C REF 21-29. REMOVED AND REPLACED DUCT ON #1 PACK TO RAM AIR CONNECTION IAW AMM 21-51-03 AND REMOVED AND REPLACED # 1 PACK VALVE IAW AMM 21-51-01, OPC GOOD. REPLACED LH MUFFLER IAW AMM 21-24-01. C/W EO# EM-2100-048 SATISFACTORY. CLEARED MEL 21-29. PRIMARY INLET LH DUCT P/N 816618-1