What was found
LEADING EDGE SLAT SYSTEM ALTERNATE LEADING EDGE SLATS PROBLEM WAS ENCOUNTERED BY THE FLIGHT CREW WHICH IS NOT COVERED IN THE FAULT CODE DIAGRAMS. LE SLAT ASYM EICAS MSG DURING FLT LE SLAT ASYM EICAS ALSO ON FINAL. PER TECH SUPPORT FOUND PSEU FAULT WITH PROX SENSOR NO. 284, INBOARD SENSOR ON NO.3 LEADING EDGE SLAT. TARGET GAP AT THIS LOCATION IS AT THE MAX OF INSTALATION RANGE. REMOVED AND REPLACED S284 LEADING EDGE SLAT SENSOR SWITCH. OPS CHECKED GOOD. NO FAULTS FOUND ON PSEU. REF AMM27-88-00, AMM27-88-01.