What was found
(CAN) RE-OCCURRING DEFECT 2008/10/21 -FLIGHT CREW REPORTED NR 4 DISPLAY UNIT FLICKED ON START-UP. FAULT COULD NOT BE DUPLICATED AND WAS SWAPPED TO NR4 POSITION FOR TROUBLESHOOTING PURPOSES. 2008/10/22 -FLIGHT CREW REPORTED NR3 DISPLAY UNIT FAILED AT THE TOP OF DESCENT. NR 3 DISPLAY UNIT DEFERRED IAW MEL. 2008/10/24 -NR 3 DISPLAY UNIT REPLACED WITH REPAIRED UNIT FROM MFG AND CHECKED SERVICEABLE IAW AMM 34. 2008/10/30 -MX REPORTED NR 3 DISPLAY UNIT STARTING FLASHING INTERMITTENT WHITE DIAMONDS AND BLACK SCREEN DURING EXTENDED OPERATION. NR 3 DISPLAY UNIT DEFERRED IAW MEL. RE-OCCURRING DEFECT FORM GENERATED. TEAR DOWN REPORT OF THIS UNIT IDENTIFIED THIS AS BEING THE REASON FOR REMOVAL FROM PREVIOUS AIRCRAFT. 2008/11/04 -NR 3 DISPLAY UNIT REPLACED WITH REPAIRED UNIT FROM MFG AND CHECKED SERVICEABLE IAW AMM 34.