I need the schematic or SERVICE MANUAL of Sharp 903sh

[denjhang]

I am currently working on the Yamaha MA-7 chip, but there is a lack of information. I have been looking for it for a long time without any progress. I learned that Sharp 903sh has this chip built in. And dozens of models since 804sh and 903sh have used this audio chip.
Who can help me.

[denjhang]

I don’t need the User Manual, it does not contain any schematics