What was found
LFF-DFW - ON FINAL, CREW SELECTED FLAPS TO 45 DEGREES. CREW RECEIVED A SINGLE CHIME ELECTRICAL MESSAGE ON MAP. AT THE SAME TIME, EMERGENCY BUS OFF LIGHT CAME ON. CREW PERFORMED A GO AROUND, DECLARED AN EMERGENCY, AND LANDED SAFELY. MAINTENANCE REPLACED CIRCUIT BREAKER 0470 AND INSPECTED WIRING. NO DEFECTS WERE NOTED. OPERATIONAL CHECKS WERE GOOD. AIRCRAFT RETURNED TO SERVICE. (M)