What was found
LOUD SQUEAL ABOVE SEAT 2A. REMOVED PSU ABOVE SEATS 2A & 2B, REMOVED SIDEWALL CEILING PANELS ABOVE ROWS 2 & 3 LT SIDE. AIR ESCAPING FROM RISER DUCT WHERE IT ATTACHES TO INDIVIDUAL AIR SUPPLY DUCT ABOVE SIDEWALL AT ROW 3, ADJUSTED & SECURED CLAMP, NO NOISE NOTED. FLIGHT ATTENDANT SAYS THERE IS A HIGH PITCH NOISE AT SEAT 1A WINDOW OPERATED PACKS, NO SQUEAL , PHYSICAL CHECK , DOOR SEAL 1L, WINDOWS AT 1A,2A,3A EXTERIOR & INTERIOR ALL APPEARS OK. VERY LOUD SQUEAL ROW 1-2 NEAR WALL-FLOOR. PRESSURIZED AC, FOUND CAPT AOA SEN OR ATTACHMENT SCREWS LOOSE, SECURED. ALSO FOUND FIRST OFFICERS AOA BLANKING PLATE CLOCKED WRONG. REINSTALLED IAW SAME MM.