What was found
FLAP DRIVE CAUTION MSG ILLUMINATES WITH FLAP EXTENSION. FLIGHT LANDED SAFELY. REMOVED FROM SERVICE. EXTENDED FLAPS AND ACCOMPLISHED GVI OF FLAPS AND ACTUATORS. NO DEFECTS NOTED. RETRACTED FLAPS TO 5 DEGREES. FERRIED AIRCRAFT. R AND R FLAP CONTROL UNIT (FCU) IAW Q400 AMM TASK 27-51-01-000-801/400-801. PERFORMED FUNCTIONAL TEST OF THE FLAP CONTROL SYSTEM REF WITH Q400 AMM TASK 27-51-00-720-801. OPS TEST NO GOOD. REMOVED FLAP POWER UNIT (FPU) IN IAW Q400 AMM TASK 27-52-01-000-801. INSTALLED FLAP POWER UNIT (FPU IAW Q400 AMM 27-52-01-400-801. PERFORMED FUNCTIONAL TEST OF THE FLAP DRIVE SYSTEM IAW Q400 AMM 27-52-00-720-801. OPS TEST GOOD. NO FAULT CODE FOUND. NO FURTHER DEFECTS NOTED. AIRCRAFT RETURNED TO SERVICE.