As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EICAS MSG L/E SLAT DISPLAYED WHEN FLAPS TO 30 DID NOT FULLY RETRACT AFTER LANDING. AFTER SEVERAL RESETS, SYMPTOMS REOCCURRED. EXTENSIVE DIAGNOSTIC SUGGESTED TARGET STABILITY PROBLEM. REPLACED NR 4 LE SLAT OUTBD UPPER TARGET, ROLLER AND BOLT. POST-REPAIR BITE TEST OF FLAPS & SLATS OK. AIRCRAFT RETURNED TO SERVICE. NO REPEAT OF ASSYM INDICATIONS.