What was found
SIN - PASSING FL260 IN CLIMB, AIRCRAFT EXPERIENCED BUFFET AND VIBRATION. CHECKED CONFIGURATION PAGE AND IT SHOWED THE NOSE GEAR UNSAFE. RETURNED TO SINGAPORE AT 260KTS .REVIEWED CFDS LRU FAULT - NO FAULT. PER CREW INFO ALERT SHOWN ON PILOT DISPLAY VISUAL INSPECTION ON NOSE GEAR, NO ABNORMALITIES OR DAMAGES. PERFORMED BITE TEST ON PSEU PER FIM 31-71-00 AND OK. CLEAN ALT SENSORS. AIRCRAFT OK FOR SERVICE.