What was found
AFTER INITIAL POWER UP IN DEN AT GATE, GOT FLAPS FAIL CAUTION MESSAGE. COMPLIED WITH SERVICE BULLETIN 670BA-27-025 FOR FLAP WIRE HARNESS CONNECTOR REPLACEMENT. SERVICE BULLETIN 670BA-27-025, REVISION C, FLIGHT CONTROLS, FLAP SYSTEM, CHANGE THE ELECTRICAL CONNECTORS AND BACKSHELLS OF THE FLAP BPSU HARNESSES PART -A-, INCORPORATED. REPLACED LEFT FLAP BPSU PER AMM 27-52-03. MECHANICALLY AND ELECTRICALLY RIGGED BOTH FLAPS IAW AMM 27-52-00. OPERATIONAL CHECK GOOD.