What was found
AFTER TURNING WING ANTI ICE ON, "WNG A-ICE 1 DISAG" LEVEL 2 ALERT DISPLAYED COMPLIED WITH QRH PROCEDURES. APPROX A MINUTE LATER LEVEL 3 AIR MANF 1 FAIL ALERT DISPLAYED. ACCOMPLISHED QRH PROCEDURES. REMOVED AND REPLACED NR 1 FAN AIR VALVE AND SENSE LINE IAW AMM 36-13-04-4. RAN ENGINE NR 1 ENGINE PER JRH. CHECK WING ANTI-ICE WITH ENGINE AIR IAW AMM 30-11-00-5, OPS CHECK NORMAL. PERFORM AIR SYSTEM TEST, TEST PASSED. CHECK PENEMATIC MANIFOLD FAILURE DETECTION FOR FAULTS BALL, NO FAULTS BALL. OK FOR SERVICE.