Help to repair a Casio MT-70

[Mat Grimoure]

Hi everybody. I'm new in the forum. Im looking for a service manual for a Casio mt 70. Any information about its circuit board, block diagram or schematic will be wellcome gratefully.
This has some malfunctions, in my opinion as first diagnostic, in some partial amp section. I know that the sound is given by 2 independient 4 voices soundchips. For any reason one of those stop sounding or lose volume some times. Thanks for help

 

[CowboyNQ]

I hope you didn't buy the keyboard off this bloke:

https://www.keyboardforums.com/threads/help-repairing-casiotone-mt-70.25154/

You can buy a service manual here:

https://www.samswebsite.com/en/photofact/search/index/or/id/os/0/page/27/photofactflag/3

Caveat: Manual may be worth more than your keyboard.

 

[Mat Grimoure]

I hope you didn't buy the keyboard off this bloke:

https://www.keyboardforums.com/threads/help-repairing-casiotone-mt-70.25154/

You can buy a service manual here:

https://www.samswebsite.com/en/photofact/search/index/or/id/os/0/page/27/photofactflag/3

Caveat: Manual may be worth more than your keyboard.

No, i dont, my casio work almost fine exept for that issue. Thanks for the suport