Vintage Synth Repair

You can perform a test routine: when switched on, press Voice + Bank  
D + 8 together. There are tests for audio output somewhere near the  
end. You can select individual tests manually, ENTER will start each  
test.

Exact description of tests is in the Service Manual of SY99 which you  
can find in Files section of SY99 yahoogroup.

Good luck!

Daniel Forro


On 21 Aug 2009, at 1:21 PM, brofjw wrote:

> Hi. This is my first post on here. Maybe someone could point me in  
> the right direction with this: I recently bought a Yamaha SY77 in  
> pretty good condition. However, when I play it I notice that the  
> paired left & right main outs don't play in true stereo at all. The  
> left and the right are playing the same monaural stream. None of my  
> other synths are doing this while plugged into the same inputs on  
> my mixer. Also, when I plug headphones into the SY's headphone  
> jack, the true-stereo effect is perfect. But the mains are screwed  
> up. Does anyone have any idea of this? Is there a D/A output  
> converter malfunctioning? Is one of the outs shorted causing it to  
> follow the other one verbatim? Is there an effects block that has  
> settings for true-stereo and monoaural outputs? Any suggestions are  
> welcome.