What was found
FLT 429 - MIA-MEX - AIRCRAFT RETURNED TO RAMP AS CONSEQUENCE OF SLAT DISAGREE LIGHT COMES ON STEADY DURING TAXI. SLATS OPERATION WAS CHECKED, THE RIGHT AND LEFT PROXIMITY SWITCH CIRCUIT BREAKER WAS RESET AND WAS PERFORMED A BITE TO THE STALL WARNING COMPUTER GIVING A FAIL IN THE ALFA VANE SENSOR AND SLAT INDICATION. THE SYSTEM WAS RESET AND THE FAIL CAME RIGHT, TESTS OK IAW MM 27-40-00. (M)