Vintage Synth Repair

I have. If you need I can took relevant pages from that big PDF and  
send. Or send whole SM somewhere, it has over 6 MB.

CN1:
Pin 1+2 = + 5 V
Pin 3+4 = Ground
Pin 5 = AG (is it analog ground?)
Pin 6 = - 15 V
Pin 7 = + 15 V
Pin 8 = VM (??? - it goes from +line directly after diode and  
capacitor, before +15 V regulator, and continues to another  
transistor stabilizer on another PCB, and then to the base of  
transistors which are directly at all output jacks and open way to  
signal).

Daniel Forro


On Mar 31, 2011, at 4:50 PM, Geoff Wood wrote:

> Hi folks,
>
> I'm replacing the 110v PSU in one of these - have located an  
> equivalent (not
> Yamaha)  230v SMPS with +5V and +/-15V.
>
> I have the commonly-available Service Manual off the net, but this  
> does not
> include schematics or a description pin-out of the PSU connector.   
> Also the
> overlay seems to show one fewer pin on the DC-output connector than  
> the than
> the Real Thing actually has.
>
> Now, it was easy-peasy to figure out the 5V (pin1+2)  and +15  
> (pin8) and
> -15V (pin 7), and two commoned earth pins (3+4), but there are two  
> more pins
> pins (5 and 6) with separate tracks leading away. I can no longer  
> check what
> is on them voltage-wise or whatt their purpose is.
>
> Any ideas, or anybody have the schematics ?
>
> cheers
>
> geoff