What was found
TE FLAP ASYM CAUTION DEBRIEF CREW, AT APPROACH FLAPS TO 1 TRAILING EDGE ASYM CAUTION LIGHT. QRH ALLOWED THEM TO L.E. ALT AND LAND WITH FLAP LOCKED UP. LANDING SPEED WAS AT ABOUT 180 KNOTS (MADE GRIPE TO CHECK FOR HOT BRAKES). ALSO PILOTS SHOWED PIC OF FLAP/SLAT ELECT. REF FIM 27-FCDIAG. T-S TO FAULT CODE 27 51 02. CODE LEADS TO FIM 27-51 TREE 812. T-S REF FIM 27-51 TREE 812, RETURNED L.E & T.E. BACK TO NORMAL. RAN BOTH L.E. & T.E. IN NORMAL & ALT, OP CKD GOOD. SO PROBLEMS WAS IN FLIGHT DURING NORMAL OPERATIONS. ORDERED FSEU-1. REPLACED FSEU 1. REF AMM TASK 27-51-01-422-011. FSEU TEST OK REF AMM TASK 27-51-01-722-005.