Rokq22:

I'll assume that your solo is MIDI and not a RealTrack.

- check to see which "voice" is being used for the solo. It may be on the Melody or Soloist button.

- check to make sure that button hasn't been set to "Mute"

- check to see if the volume of that button is turned up to (say) 127

If that doesn't fix things, give us some more info on where your "solo" is

Good luck!
LLOYD S