What was found
THE 'T-E FLAP DISAGREE' EICAS MSG DISPLAYED WITH FLAPS AT 20 UNITS. ACCOMPLISHED BITE TEST OF FSEU AT GATE IN SFO WITH FLAPS STILL AT 20 UNITS. FSEU IS THE OLD NON-DIGITAL TYPE. SHOWED FAULTS FOR M548 AND M603. PERFORMED BITE TEST PER MM 27-51-00-FIG 104, FLAPS AT RETRACTED POSITION ENDED AT BLOCK 4 THE FSEU COMPONENTS AND WIRING ARE OK. CREW REPORTED MSG APPEARED WHEN FLAP HANDLE WAS MOVED FROM 1 UNIT POS TO THE 5 UNIT POS. FLAPS WERE LOWERED TO 20 UNITS IN ALTERNATE. NOTHING UNUSUAL FELT OR NOTICED BY CREW. PERFORMED BITE TEST. TEST OK. ALSO RAN SLATS FLAPS IN EACH POSITION FROM 1 TO 25 UNITS, NO FAULTS OR EICAS MESSAGE, ALSO PERFORMED THE BITE TEST AGAIN ON FSEU NO FAULTS INDICATED. NO RECURRENCE AS OF 12/24/08.