What was found
WHEN WING AND TAIL ANTI-ICE SELECTED RECEIVED BLEED AIR 1 OFF, BLEED AIR 2 OFF, PACK 1 OFF, PACK 2 OFF ALERTS. THEY TRIED ESC IN MAN AND SWAPPING CONTROLLERS - NO HELP. NR 2 BLEED AIR WOULD SHUT DOWN FIRST FOLLOWED BY NR 1 BLEED APPROX 30 SEC LATER. SELECTING TAIL A/I ONLY CAUSED NO ABNORMALITIES. MX INTERROGATED MFC, PSC1, PSC2, ALL ACC'S, AND ESC FOR CURRENT FAULTS AND FAULT HISTORY. ONLY ONE LATCHED FAULT IN PSC1 - TI2 SENS, INTMT AT 19:22, JUST AFTER T/O AT 2500 FT. PERFORMED DECAY CK IAW JRH 8-8 WITH ALL PASSING MIN LIMITS EASILY: NR1 11/7.4, NR2 29/19, NR3 13/9.3. MSC TERMINATED COMMUNICATION SEVERAL TIMES DURING INTERROGATION. T/S CONTINUES. REMOVED AND REPLACED NR 1 ENG HIGH STAGE VALVE REF AMM 36-11-03-4 STILL NEEDS OPS CHECK REF AMM 36-11-03-5, ALSO 6 EA PILOT VALVE HEATERS OPS CHECK NORMAL. REPLACED NR 2 HIGH STAGE VALVE IAW MM 36-11-03-4. RAN ALL 3 ENGS. ALL HI STAGE VALVES CHECKS GOOD IAW MM 36-11-03-5. PREVIOUSLY REPLACED LT WING DP SENSOR OPS CK GOOD IAW MM 30-11-02-5. WING AND TAIL ANTI-ICE SYSTEM OPERATIONAL CK GROUND CK GOOD.