Yamaha MM6 Keyboard Display is blank and No sound? Any ideas on fixing/resetting

[aamozafari]

Some kids played with our Yamaha MM6 keyboard. Don't know what they did.
Now the display is blank-blue color and no sound!
Power does come on but nothing more.
Any ideas on how to reset/fix?

 

[djvlive]

Some kids played with our Yamaha MM6 keyboard. Don't know what they did.
Now the display is blank-blue color and no sound!
Power does come on but nothing more.
Any ideas on how to reset/fix?

Did you get this figured out at all? I'm having a similar problem.