Hi is yours suddenly sounding wrong?
Did you check if the sound settings changed? Maybe its default settings have been changed... For example, the Roland V-Piano has an option to make it sound out of tune on purpose (to mimic the style of bands like The Fray, etc.)
The first thing to check is that you have not accidentally pushed the "transpose" button and simply shifted the entire keyboard over a few semi-tones.
There is also a "tunning" setting that adjusts the tune to A=440 or whatever standard you want. You may have messed with that too.
Also the DP can be set to other not-equal, historic temperaments that would sound out of tune to anyone born in the 20th century.
Odd voltage spikes or other glitches (or the cat walking on the controls) could have altered these settings even if you did not.
But Is it just a change in timbre with maybe some large harmonic overtones added or has the pitch shifted? In other words does it still sound like a clear piano tone or is there some "fuzz"
If it is fuzz and but not pitch shift then you've got audio section problems.
If thats the case then you will need to have this professionally done by a local music in repairman. If you don't know of one near you please send me your state and town I will see if I can recommend one nearby.
In any case, I will stick with you until this is complete.
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Thank you and have a nice evening!