What was found
AFTER TAKEOFF AT VR, TR-3 FAIL LEVEL 1 ALERT, DISPLAYS 4-6 AND MCDU NR 2 WENT BLANK. RAN QRH. AT BLOCK IN WITH EXTERNAL POWER CONNECTED TR3 CAME BACK ON. OPS CHECKED THE R2-18 IAW AMM 24-25-03-2, TR3 OPS NORMAL IAW AMM 24-31-01-2, AND WDM 24-57-07.