tek 453 timebase not working

[m3vuv]

hi all ive a 453 tek(late fet model),it was working fine last night but today the timebase knob wont work,it turns and clicks but doesent alter the time base,is the trace doesent change,any ideas where to look?,,the x10 position still works,its as if its stuck on one setting,cheers Paul m3vuv.

[m3vuv]

sorted,it was the aluminium boss loose on the shaft!!