Well it was a brief honeymoon. My nearly new GP-510 has gone off the deep end. The sound engine or effects processor has somehow corrupted its internal parameters. This is the second time it has happened. The previous time, I gave up and went to bed. The piano was back to normal by morning as if nothing had happened.
The problem starts with the grand piano sounds: loss of stereo separation, loss of depth/volume, and certain notes (F#3, G3, G#3, and a cluster in the bass as well) sound quiet and thin. If you've ever heard an acoustic piano with two of three strings muted on a note during tuning, it's not unlike that.
Selecting different tones, such as Harpsichord, or Electric Bass, provide stranger sounds... like you are standing at the very back of an enormous hall and hearing only reverberated sound.
I managed to record some of the weird sounds onto a USB stick. When played back, they either sound just as weird, or different, but still not right.
Playing a Concert Play piece, such as Raindrop, results in the provided piano track sounding incredibly distant, while the orchestra sounds almost normal, but not quite right.
I have tried:
Factory Reset in the menu, which does reset all settings, but is not a cure for this behavior.
Adjusting hall reverb and position, as well as toggling through various scenes.
Adjusting EQ, etc.
Power off and unplug the DC Power supply, let the piano sit for a few minutes.
Nothing has helped, other than last time of leaving it overnight, unplugged.
Anyone experience this and know of a fix, like a true hard reset? Is this a usual bug? I'm thinking a call to my dealer is in order.