What was found
FLAPS FAIL MESSAGE AT RETRACTION AFTER LANDING, FLAPS AT 30 DEGREES. UPON POWER DOWN AT GATE AND RE-POWERING, MESSAGE WENT AWAY. REMOVED AND REPLACED RIGHT BPSU WITH SERVICEABLE UNIT IAW 27-51-10. FLAPS OPS CHECK GOOD. P/N ON: 855D100-9, S/N ON: 393B, P/N OFF: 855D100-7, S/N OFF: 206.