E1 - Press one of the two Mode keys. If the error message re-appears, a system error has occurred (operation no longer possible) ... remedy:- contact the Service Department!
I can't find the Service Manual, but the Users Instructions
is (are) quite good.
But "Error 1" must be something a bit drastic, I would have thought (or even, basic). Like failing a POST at start-up, for instance. Does the unit have an on-board back-up battery, I wonder. What have you tried so far?
By the way, I can't remember if I've linked to this
one before - but it's an interesting read for anyone interested in operating microscopes (and I'm still looking for Part 2).