What was found
AFTER TAKEOFF LT MLG AND MLG DOOR FAILED RETRACTION, AMBER INDICATION ON MLG DISPLAY. VIBRATION & NOISE UNTIL GEAR RETRACTED APPROX 25 SECS. INSPECTED AND FOUND LGECU A FAULT 1. MLG WOW TO SPC & LGECU B FAULT 1. WOW TO SFOJ 2. BOTH FAUL TS ARE ACTIVE IN THE FAULT HISTORY. PERFORMED BOTH BIT TEST ON CHANNLE B FOR LGECU & BOTH FAILED. DOWNLOADED AND SENT ALL FAULT TS HISTORY TO CRC. PERFORMED ALL TROUBLESHOOTING IAW CRC. RERACKED LGECU & PERFORMED MLG SWINGS. NO DEFECTS. BOTH FAULT CODES CLEARED. WORK DONE IAW AMM 32-31-09, 32-30-00, & 07-10-01. REMOVED MLG ECU & INSTALLED A NEW ECU IAW AMM 32-31-09. PERFORMED OPS CHECK IAW AMM 32-31-09. CKD GOOD.