What was found
PASSING 17000FT, FLAPS RETRACTED, CLEAN CONFIGURATION, RECEIVED L/E SLAT ASYM EICAS ALONG WITH T/E CAUTION LIGHT. AT DESTINATION, FLAPS COULD NOT EXTEND WITH HYD EXTENDED FLAPS IAW QRH ELE WITH ALTN FLAP SWITCH. PERFORMED BITE ON ALL 3 FSEU'S. NO CURRENT FAULTS, BUT FOUND "SLAT LOSS" ON FSEU NR1 ON LAST FLIGHT LEG. USED PROCEDURE FIM 27-81-00, FIG 105. NO GROUND FOUND AT PIN B6 ON CONNECTOR D3312B. IAW FIM, FSEU NR1 NEEDS REPLACED. R & R NR1 FSEU IAW MM 27-51-01. SYS OPERATES GOOD, WITH NO FAULTS. CAT STATUS DOWNGRADED TO CHECK III FOR ALL THREE A/P'S.