I am not a DIYer and have never had the CZ-230S. I am pretty sure I have seen other people talk about replacing the LCD foil on other CZs, but that would have been a decade or so ago. No sure if that's your problem. I vaguely recall someone asking if the CZs could be retrofitted with LCDs with a backlight and possibly someone mentioned where to pull the power from. Again, not sure if that is your problem, and these memories are from when my brain wasn't so old.
I think there are still some qualified DIYers here who can provide more specific details.
On the outside chance I will stumble on the posts or sites I saw, I will share them.
Steve