I don't know the answer.
But given the holidays, this is what I would try whilst waiting for those Segway experts to respond.
It 'smells' like most of the gear is working, and maybe you have had a glitch ( did you have any thunderstorms or power blackouts ? ).
So I would try to re-start it.
To do a cold reset, remove both batteries.
Leave them off for a decent time, say 15 minutes.
( observe the battery date codes, or just post the first 6 digits here ).
Re-fit the batteries and see what happens.
Good luck.
Michael
www.dgbint.com