What was found
ON T/O CLIMBING OUT AT 5000FT, MASTER WARNING ILLUMINATED WITH -AIR MANF 2 FAIL- ALERT DISPLAYED AIR SYSTEM SHOWED NR 2 INDICATING RED WITH NR 2 BLEED OFF AND PACK 2 & 3 OFF. SYNOPTIC WARNED NOT TO PRESSURIZE MANIFOLD NR 2 RED -MANF- DISPLAYED ON OVERHEAD PANEL. RETURNED TO IND. PERFORMED AIR SYS TEST AND FAILED. AIU 1 CURRENT FAULTS WERE ALL 3 SYSTEMS TRIED NEW MANIFOLD FAULT DETECTION CONTROLLER AND WORKED NORMAL. COULD GET NR 2 MANIFOLD FAIL LIGHT WITH OR WITHOUT AIR APPLIED. PERFORMED NR 2 DECAY CHECK WITH ENG AIR PER MM SUPP. PERFORMED NR 2 DECAY CHECK WITH APU AIR PER MM SUPP. A/C OK FOR SERVICE.