How to open a Casio FX-4000P?

[Dave Britten]

(08-08-2021 12:30 PM)johanw Wrote:  I didn't even have to tune up the contrast (is that even possible on a 4000? I didn't see any keys for that) as was the case with my FX-8000G, when I replaced the batteries in that one my heart sank when I didn't see anything when I switched it on, until I got the idea to push up the contrast. That worked.

There should be a little contrast dial on the side. Same with the fc-200, and a couple other models that use that same chassis.