Hard reset MT-70?

[Macola]

Hi all,
I have gotten MT-70 and it has a specific problem. Every time I power it on it turns on different setup randomly. Everything is scrambled but every time in a different way and no keys are responding. Sometimes sound is played and some rhythm played for a second and different led lightened. Display scrambled randomly.

Considering that it wasn't used for years, possibly decades I figure hard reset might help. I saw on one guys web page that he has put lots of additional controls on his MT-70 and one of them is reset button. Does anyone knows which points on the mother board should be shortened for this?

Or if these are symptoms of some specific problem?

Thanks a lot.

 

[happyrat1]

Take a look at the CPU and find the reset pin. It should be on the manufacturer’s data sheet. Shorting that pin to ground should do the trick.

Gary.

 

[Macola]

Gonna try that, thanks.

 

[happyrat1]

Yer welcome

 

[Macola]

Old and obscure chip, data sheet nowhere to be find.

EDIT: found it.

 

[happyrat1]

Get in touch with the circuit bending crowd. They love vintage Casios and might have better specs.

Gary.