I have a Casio electric piano with weighted keys that I bought in the year 2000. I've loved it but now some critical keys suddenly stopped working -- just no sound at all -- from middle C down to the F below middle C. Most of these keys are also the same ones used to change the key -- by pressing a control button and a key that corresponds to how many half steps you want to go down. I wonder, first, whether these keys having a dual function (and therefore being probably more complicated on the back side) contributed to their breaking, and secondly, whether they can be fixed, either by me or by a professional repair person.
I've added the model number I found on the case. I'm really interested in knowing what is wrong before I speak with a repair person. Casio gave me two contacts but they are both on the other side of a mountain range and if possible, I want to find someone local. But knowing what is wrong will make that easier.