What was found
(CAN) JUST AFTER DEPARTURE AND BEFORE THE FLAPS ARE NORMALLY RETRACTED THE CREW RECEIVED A FLAP FAIL CAUTION MESSAGE. WHEN THE CREW ATTEMPTED TO RETRACT THE FLAPS THEY DID NOT MOVE AND REMAINED AT 8 DEGREES (SLATS AT 20). THE CREW ATTEMPTED A RESET IN THE AIR WITHOUT SUCCESS. THE A/C RETURNED. THE MDC INDICATED THAT THE RT INBD SKEW DETECTOR WAS AT FAULT. THE RT INBD SKEW DETECTOR WAS REPLACED AND THE FLAP SYSTEM FUNCTION CHECKED SERVICEABLE. SKEW DETECTOR P/N 5913163, S/N A2306, PART TSN 9773, CSN 5057. A/C TSN 15153, CSN 7527.