A horizontal stripe usually indicates a problem with the CCD sensor assembly.

I don't think a SD card can cause that type of problem.

If the camera has been exposed to moisture, that can cause corrosion on any of the printed circuit boards. And it usually shows up on the CCD assembly.

There is nothing you can do to fix it.
Keep an eye on it and if it gets worse, you need to get a repair estimate from Casio.

..