What was found
ON FLIGHT 3663 (LGA - GRR) WHILE AT CRUISE RECEIVED A FLAPS FAIL CAUTION MESSAGE WHILE FLAPS AT 0. AIRCRAFT LANDED SAFELY. FLAP SYSTEM FAULT WAS CLEARED WITH CREW AND MOC. PER MOC CYCLE CB'S FROM CRJ FIM MESSAGE CLEARED OK FOR SERVICE MESSAGE CLEARED OK FOR SERVICE. REMOVED AND REPLACED LEFT BPSU IAW AMM 27-51-10 OP CHECK GOOD C/W PA. FIXED FLAP FAIL, REMOVED AND REPLACED RIGHT AMP, OPS CHECKS GOOD.