Sokkia EAGL3 error code

I have a Sokkia EAGL3 laser that I have been using to dig a construction site to -1% grade. Saturday I put it in its box and yesterday when I took it out and put it on its tripod, then switched it on and the screen now says ERR- 1. It's starts turning right away, sometimes fast sometime slow. Can't adjust anything so I don't know whether it is level or not and if it is set on the right grade.



What does this code mean??:confused:



Thanks, Dennis