What was found
BOTH ENGINE BLEED AIR GAUGES READ 0 AND ACFT WOULD NOT PRESSURIZE, F/O INSTRUMENTS ALL FLAGGED, AND CAPTAINS, COMPUTER, FLAG INTERMITTENT. R & R THE CABIN PRESSURE CONTROLLER PANEL IAW AMM 21-31-25. OPS CHECK IAW 21-31-00. CAPTAIN ADI COMPUTER FLAG, NAV COMPUTER FAILED. REALIGNED IRU ACCOMPLISHED DFCS ADJ/TEST IAW AMM 23-11-00 CHECK NORMAL. CO-PILOT ADI AIRSPEED, DG AND ALTIMETER WERE FLAGGED, AIRDATA AND NAV COMPUTER FAILED. ACCOMPLISHED DFCS ADJUST /TEST IAW AMM 22-11-00, CHECK OK.