What was found
RECE'VED PACK 1 VLV CLOSED AND BLEED 1 CLOSED ON TAKE OFF. RECYCLED 4 TIMES + FOLLOWED QRH AND COULD NOT GET THE PACK TO STAY ON. C/A-DEFERRED PER MEL 21-28. AUTH # 050962D-C. MEL HAS TO BE CHANGE FROM 21-28 TO 21-30, DUE TO WRONG MEL ISSUE ON "N" REG. ITEM DEFERRED PER MEL # 21-30 AUTH # 050962D-C AS PER MOC # 680993. REMOVED AND REPLACED PIPE, COUPLINGS, AND CLAPS FROM DUAL TEMPERATURE CONTROL VALVE TO HEAT EXCHANGER IAW AMM 21-51-02, OPS CHK GOOD, LEAK CHK GOOD. MEL RESTORED.