What was found
FLAP POWER CAUTION ILLUMINATED SELECTING FLAPS 15-35 DEGREES. FLAPS REMAINED AT 15 DEGREES. COMPLIED W/ RESET PROCEDURE IAW EMERGENCY/ ABNORMAL CHECKLIST AND THE LIGHT REMAINED ILLUMINATED. LANDING UNEVENTFUL. RESET FLAPS PER SL DH8-400-SL-27-002A WITH ENGINES RUNNING OPERATED FLAPS THROUGH FULL RANGE OF TRAVEL 0-35 DEGREES 2 TIMES. NO CAUTION ILLUMINATED. INTERROGATED CDS FOR FAULTS NONE FOUND. C/W FIM TASK 27-50-00-810-802 AND PERFORMED OPS TEST OF WING FLAPS OPERATING FLAPS THROUGH SERVERAL CYCLES. FLAP POWER CAUTION DID NOT ILLUMINATE. NO FURTHER DEFECTS NOTED. COULD NOT DUPLICATE. RETURNED TO SERVICE. NO PARTS REPLACED.