musical keyboard

Hi. I have a 1992 Ensoniq KT76 digital piano. It works, but the output volume is very very low, even when the volume fader all the way up (no noise from fader), either through earphones or the 1/4 jack outputs in the back, so i'm thinking something might be wrong with the amplifier inside? Could...

Hello, and thanks for reading this post, I have a Roland D-10 Synthesizer that plays all the keys after you power the unit up. But if you press E,F,Gb,G,Ab,A,Bb,B. on the second to lowest octave they play once at a maximum of 127 velocity and sustain at that velocity until the unit is...