Chosen Solution
How to repair the display of a Casio FX-991ES Plus Calculator
Hi @angeltwayana , What is the problem with the display? If it needs replacing unfortunately, I’ve been unable to find a replacement LCD screen. You may have better luck. Given the cost of a new calculator it may be uneconomically viable to replace the screen even if you could find a replacement part. If it’s just that a line may be missing in the display or certain sections of the display is not working, you could always try dis-assembling the calculator and inspect the display module connections to the systemboard in case it is a faulty connection that is causing the problem. Always remove the power source or battery from electronic equipment before starting any repairs etc.
I would recommend buying an fx-82es and swapping screens, as they are the exact same screen.
