I baught a recently serviced second hand alti 2, it arrived reading 11,500ft so I reset it (and it was very stiff because of the o-ring) then a day later its reading 190ft...
So my two queries are about the o-ring, I remember during my training it was veery easy to adjust the dial and the altimeters are the same model... and the movement of the dial keeping in mind the unit hasn't been touched and my house hasn't risen almost 200ft!