hi all. Our KN6500 is not working properly. Mostly the piano sounds when played have a background of some percussive effect. Its like someone is playing a cymbal ??
The keyboard is played mostly in split mode.

We took it to a repair shop but they didnt fix it. They put it back to factory presets.

Is it possible to have something wrong that we can fix without new parts if its been reverted back to factory presets and still has problems?

..also, what does ''initialising'' mean??.. ive seen it mentioned here, i did think it was reverting back to factory presets.

All input gratefully received.. thanks