Yamaha CLP-230 tuning issue

by Steve Chesser
(Springfield, PA)

This is going to sound strange, but for some reason, the black keys on my CLP-230 seem to be out of tune with the white keys for some reason. If I just play on the white keys (chords, scales) - no problem. As soon as I play a chord that uses the black keys, it's obviously out of tune. Very strange. Is this a known issue with a verifiable answer? Any other ideas?