There are few plastic hooks that hold the pieces together. You can open it by using force. Grab as good grip as you can from both halves and just pull. But as I mentioned, this may break the hooks. I didn't.
Another way to open the hooks is to insert a thin screwdriver, palette knife etc. to the seam of the two plastic pieces. The hooks are located relatively close to the top of the case, so push the palette knife into the casing through the seam to open the hooks.
I had my unit examined by a professional electronic repairmain and his verdict was that mine had fried the integrated circuit. The board still received current, but the control circuit did not do anything.
I think the grey bezel around the display is clipped with plastic clips. I tried to pry it open with a palette knife but didint mange to do it.