Vintage Synth Repair

Thanks Miquel,
I have a schematic but that is all. Does your manual have any diagnostic/troubleshooting help? Or is it more of a user manual? Does it have specs for voltage regulation/ripple? Any text on troubleshooting the computer section would be appreciated.


--- In vintagesynthrepair@yahoogroups.com, "Miguel Mendoza" <miguel@...> wrote:
>
> I'm not very sure but perhaps there is any voice that can't be tuned properly (regarding the led behaviour). Mine one is working properly but I have to wait 2-5 minutes until the knobs start to work fine, mainly the filter cut off. 
> 
> I have a good service manual but only on paper, I bought it in Manual Minor. If you have any concrete question about the schematics perhaps I could help.
> 
> Is the hum coming into the audio path?
> 
> 
> 
> 
> From: Frank Simon 
> Sent: Wednesday, June 30, 2010 1:56 PM
> To: vintagesynthrepair@yahoogroups.com 
> Subject: Re: [vintagesynthrepair] Re: Prophet 10
> 
> 
>   
> 
> OK, That's what I'm after. Mine does hum but the Regulated voltages are all correct. I did make a comment on ripple but not so sure that is an issue. I would like to move on to the computer board after I bless the PSU. Can anyone guess why sometimes the the LEDs light and and somtimes they don't? Does that seem to be Processor related? I would rather chase audio. Also can I unplug all the boards off the Computer board except power for troubleshooting?
> 
> 
>   ----- Original Message ----- 
>   From: Miguel Mendoza 
>   To: vintagesynthrepair@yahoogroups.com 
>   Sent: Wednesday, June 30, 2010 4:59 AM
>   Subject: Re: [vintagesynthrepair] Re: Prophet 10
> 
> 
>     
> 
>   I don't hear any hum in my Prophet 10 
> 
> 
>   From: Frank Simon 
>   Sent: Wednesday, June 30, 2010 5:30 AM
>   To: vintagesynthrepair@yahoogroups.com ; SequentialCircuits@yahoogroups.com 
>   Subject: [vintagesynthrepair] Re: Prophet 10
> 
> 
>     
> 
>   Are there any Prophet 10 owners that can answer a question for me? Can you hear your transformer hum when you power up?
>   Frank
>     ----- Original Message ----- 
>     From: Frank Simon 
>     To: vintagesynthrepair@yahoogroups.com ; SequentialCircuits@yahoogroups.com 
>     Sent: Monday, June 28, 2010 11:24 PM
>     Subject: Prophet 10
> 
> 
>     My P10 is wacko. Sometimes I turn it on it lights up and acts like it wants to work but if I cycle the power nothing will light except the tune LED as if it is in tune mode but doesn't time out. If I cycle power something different may happen. I think the PCB3 board has issues would anyone agree? All Power supplies are good with DVM but I see noise ripple on supplies with .2 to .5V that seems high to me. It is not 60 cycle ripple but very random noisy ripple. Not sure of best trouble shooting approach of this board. My P10 shematic is freeby with poor zoom in ability. My P5 is better but refernce designators and power supplies seem different. Anybody got a good service manual or advice?
>     Frank
>