Yamaha CS80

found one. Will need $50, but have to test it for you first. Will do that today.
Regards
Tim


On Saturday, July 19, 2014 4:19 AM, "Robert Stewart bob@... [yamahacs80]" <yamahacs80@yahoogroups.com> wrote:
 


  
Hi Tim

Any news on the 150?


Cheers



Bob

On 18/07/2014 08:25, Tim Conniff tconno@... [yamahacs80] wrote:

  
>dummy load may become pivotal in determining the source of the issue.
>Alternatively, of course, you could substitute another source of power if available, and i don't mean another cs50 supply, I mean ANY other capable source. 
>Given the whine's prevalence on the power lines, you might also want to disconnect the juice to the voice cards all at once and see if it's still being heard, just to further rule out stuff.
>Btw, I have found a 150, just haven't had time to check it yet.
>good luck
>Tim
>
>
>
>On Thursday, July 17, 2014 11:38 PM, "Bob Stewart bob@... [yamahacs80]" <yamahacs80@yahoogroups.com> wrote:
> 
>
>
>  
>I don't have a dummy load unfortunatley, but did short the sense lines and look at it.
>Seemed to be OK, but might need to run it for a while to let it warm up first.
>
>
>Might just be that something's beginning to fail under load. Just really annoying that it's showing up on all the power lines. Might have a chance to look at it further today, but have a MonoPoly to tune, and a Prophet 5 to diagnose over at a clients.
>
>
>
>
>On Friday, July 18, 2014, Tim
                                    Conniff tconno@... [yamahacs80] <yamahacs80@yahoogroups.com> wrote:
>
>  
>>Can you remove the supply, give it all needed dummy loads, and or short sense lines to their respective power lines? Then you can determine if it is strictly from the supply, or a function of the load inducing a resonant freq, or other anomaly. I assume you have a scope.
>>Tim
>>
>>
>>
>>On Thursday, July 17, 2014 11:04 PM, "Bob Stewart bob@... [yamahacs80]" <yamahacs80@yahoogroups.com> wrote:
>> 
>>
>>
>>  
>>Only two fuses on the CS50.
>>Voltages are all there, but there's this signal sitting on top of them.
>>Synth works fine other than the whine, and a duff LFO chip.
>>
>>
>>Thinking it's got to be a duff semiconductor/ IC on the PSU :-(
>>
>>
>>B
>>
>>On Friday,
                                                          July 18, 2014,
                                                          laurie laurie@... [yamahacs80] <yamahacs80@yahoogroups.com> wrote:
>>
>>  
>>>are all 3 fuses intact?
>>>
>>> 
>>>
>>>---- On Thu,
                                                          17 Jul 2014
                                                          11:14:08 -0500 bob@... [yamahacs80]<yamahacs80@yahoogroups.com> wrote ---- 
>>>
>>>
>>>  
>>>>Hi 
>>>>
>>>>
>>>>Just servicing
                                                          a CS50, and
                                                          it's
                                                          constantly
                                                          outputting a
                                                          whine of about
                                                          4120Hz.
>>>>
>>>>Unit came to
                                                          me a bit
                                                          battered as
                                                          the PSU had
                                                          shaken loose
                                                          and trashed a
                                                          few things
                                                          inside.
>>>>PSU PCB had
                                                          become
                                                          cracked, so
                                                          replaced that
                                                          with a working
                                                          one purchased
                                                          from
                                                          Synthparts.
>>>>Recapped the
                                                          new PCB before
                                                          I fitted it.
>>>>
>>>>I've done the
                                                          usual, changed
                                                          the logic on
                                                          the KAS board
                                                          and the S/H
                                                          board,
                                                          replaced power
                                                          decoupling
                                                          caps
                                                          throughout
                                                          etc.
>>>>
>>>>The only
                                                          difference is
                                                          that
                                                          originally it
                                                          took a minute
                                                          or so to
                                                          manifest...
                                                          now it
                                                          manifests
                                                          immediately.
>>>>
>>>>I can see the
                                                          signal on all
                                                          power lines.
>>>>
>>>>
>>>>Any thoughts?
>>>>
>>>>
>>>>B
>>>>
>>>> 
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>
>>
>
>