Help with my casiotone, please!

Hi,

I have never posted on a forum before but I am kind of frantic right now and after a search on google, I came upon your DIY forum. I came home from a semester abroad after leaving my Casiotone MT 220 safely stored under my bed. It was working sorta fine when I left it-- the only real malfunction was that I had to push the button up really hard to turn it on, but then once it was on the only way to turn it off was by removing the battery, I figure most machines have their tricks..right? Now I turn it on and the lower keys no longer make any sound and the keys that do work don't hit the right notes, some hit the same note, some appear to hit two notes at once? I tried to open it up and see if maybe something was obstructing something else?? I have never worked with any circuit board in my life. Is there hope for my keyboard? Is there a problem I could fix, or would I be in waay over my head?

Ahh, sorry for the long post. Any information would help.

Thanks a whooole bunch,

Melissa