Oberheim Matrix-12 Repair

[loveslap]

ok here we go.  this unit was working pretty well but had a few problems with a couple voices so I started swapping chips between the 2 voice boards (12 voices, 6 per board). and somewhere along the line I screwed up. I have become more careful with this type of work now. Still makes sounds but refuses to tune. I am not sure If I have the 2 molex cables with 2 wires (but 3 pin connectors) connected correctly in positions D and E on the processor board and in C in the respective voice boards. Does this service manual indicate how to hook those up?

service manual/schematics at:
https://elektrotanya.com/oberheim_matrix-12_sm.pdf/download.html
(too big to upload directly)

 

[leo-666]

Rapid in-a-hurry question for Matrix 12 USA owners and technicians !!!

Will

http://dbwbp.com/synthbin/Oberheim%20Matrix%2012%20(Japanese%20Edition)%20CPU%20&%20Voice%20EPROMs.zip

or

http://dbwbp.com/synthbin/Oberheim%20Matrix%2012%20(Japan%20version).zip

or

https://www.vintagesynthshop.com/Oberheim-Matrix-12-OS-1-6-Rom-Firmware-bbaaaaqba.asp

work on USA matrix 12 ???

I suspect dead EPROM chips in one that I'm servicing now
and need to know can I flash my own or buy.
Probably nowhere on the net I can see a set for a US version.
Vintagesynthshop telling that those won't work on US version.
But how can it be ???
The logic components are totally the same ?

Thanks.

 

[Rob Flinn]

This is a good place to ask the questions you have

https://www.facebook.com/groups/vintagesynthrepair/

 

[leo-666]

Thanks.
Shall do