As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EICAS MESSAGE -L/E SLAT DISAGREE- ILLUMINATED WHEN THE FLAP LEVER WAS PLACED AT 1 DEGREE POSITION. FOLLOWED QRH PROC AND SLATS EXTENDED ELECTRICALLY AND FLAPS EXTENDED HYDRAULICALLY. L/E SLAT DISAGREE MSG WAS NOT ILLUMINATED DURING MTC CHECK. PERFORMED BITE CHECK ON BOTH FSEU AND PSEU WITH NO FAULTS. PUT ALTN FLAP AND L/E SWITCH BACK TO NORMAL AND RAN FLAP/SLAT SEVERAL TIMES WITH NO FAULTS. DURING FURTHER CHECK FOUND FLAP/SLAT HYD SHUTOFF VALVE LEAKING HYD FLUID. REPLACED SAME.