What was found
RECEIVED RT.REV UNLOCK CAUTION MESSAGE DURING CLIMBOUT, C/W'D QRH & SELECTED EMER STOW SWITCH, MESSAGE REMAINED, ALSO HAD AMBER REV ICON IN N1 GAUGE. M/C DID AIR RETURN TO IAD PER QRH, CREW DID NOT DECLARE AN EMERGENCY. "AIRCRAFT REMOVED FROM SERVICE" FOUND ANTI ROTATION TANG OF RH BOTTOM INNER BALLSCRE ACTUATOR BROKEN. R/R BPTTPM INNER BALLSCREW ACTUATOR IAW AMM 78-32-01, OPS CHECK GOOD. RERIGGED RH BOTTOM OUTER TOP OUTTER BALLSCREW ACTUATORS IAW 78-32-01, OPS CHECK GOOD. REMOVED PLACARD REMOVED FROM MEL. S/N OFF 9633 S/N ON