I have a Kawai ES3 digital Piano, it powers up but no sound from speaker or headphone socket.
also no response from the midi output. what issue could be?
If everything LOOKS normal but it makes no sound, I would try playing the ES3 remotely from another keyboard via MIDI. If you then get sound, you know the problem lies with the keybed (or with its connection to the main board). Since you get no MIDI Out data, I would suspect a keybed issue.
If you get no sound playing the Kawai via MIDI, then there could be any number of things causing the trouble.