Vintage Synth Repair

Hi,

I have a MKS20 that was not used for about 1 year. 2 days ago a turned
back on and now the sound is very distorted, from the main and phone
output.

If I maintain a steady notes I can hear some loop of something (of
about 2 secs) (but maybe is common in the RD1000 architecture and now
picking I'm missing it)

I can here also an echo kind of slapped one (very faint). I have non
chorus or vibrato active and there is no delay on the mixer.

I tried to clean the RL1 (the only relay on the effect board) as
suggested on the board (thanks Bob) but there is no good result.

Do you have any idea ? Any troubleshot procedure?

where I can find the pdf for the Service manual ?

thank you
Antonio

In my experience you need to replace the relay not just clean it...

--- In vintagesynthrepair@yahoogroups.com, "atuzzi" <antoniotuzzi@...>
wrote:

>
> Hi,
> 
> I have a MKS20 that was not used for about 1 year. 2 days ago a turned
> back on and now the sound is very distorted, from the main and phone
> output.
> 
> If I maintain a steady notes I can hear some loop of something (of
> about 2 secs) (but maybe is common in the RD1000 architecture and now
> picking I'm missing it)
> 
> I can here also an echo kind of slapped one (very faint). I have non
> chorus or vibrato active and there is no delay on the mixer.
> 
> I tried to clean the RL1 (the only relay on the effect board) as
> suggested on the board (thanks Bob) but there is no good result.
> 
> Do you have any idea ? Any troubleshot procedure?
> 
> where I can find the pdf for the Service manual ?
> 
> thank you
> Antonio
>

>In my experience you need to replace the relay not just clean it...

To test, it can just be temporarily shorted.

_________________________________________________________________
Watch free concerts with Pink, Rod Stewart, Oasis and more. Visit MSN 
Presents today. 
http://music.msn.com/presents?icid=ncmsnpresentstagline&ocid=T002MSN03A07001

I tested shorting it, and I'm still getting distortion.
on all sounds and with or without tremolo and chorus.

The distortion is kind of pitched noise/saw like. Is always tuned to
the current played note.

thank you
at


--- In vintagesynthrepair@yahoogroups.com, "Scott Nordlund"
<gsn10@...> wrote:
>
> >In my experience you need to replace the relay not just clean it...
> 
> To test, it can just be temporarily shorted.
> 
> _________________________________________________________________
> Watch free concerts with Pink, Rod Stewart, Oasis and more. Visit MSN 
> Presents today. 
>
http://music.msn.com/presents?icid=ncmsnpresentstagline&ocid=T002MSN03A07001
>

Sounds like an electrolytic capacitors problem to me. Please test
those in the power supply section and those in the output too.

The best way is to use a capacitometer. But if you only got a
multimeter, you can test them using OHM. If you get around 0, the cap
is good; high resistance, it's dead or dying.

For best results, desolder one leg in order to avoid picking up the
resistance of the circuit.

Hope that'll help you

Steph
--- In vintagesynthrepair@yahoogroups.com, "atuzzi" <antoniotuzzi@...>
wrote:
>
> 
> I tested shorting it, and I'm still getting distortion.
> on all sounds and with or without tremolo and chorus.
> 
> The distortion is kind of pitched noise/saw like. Is always tuned to
> the current played note.
> 
> thank you
> at
> 
> 
> --- In vintagesynthrepair@yahoogroups.com, "Scott Nordlund"
> <gsn10@> wrote:
> >
> > >In my experience you need to replace the relay not just clean it...
> > 
> > To test, it can just be temporarily shorted.
> > 
> > _________________________________________________________________
> > Watch free concerts with Pink, Rod Stewart, Oasis and more. Visit MSN 
> > Presents today. 
> >
>
http://music.msn.com/presents?icid=ncmsnpresentstagline&ocid=T002MSN03A07001
> >
>

ebay item 190089602919 should be compatible

--- In vintagesynthrepair@yahoogroups.com, vco3@... wrote:

>
> HI does anyone know where to get the relay for the mks20? thansk jeff
> 
> 
> 
> for ambient electronic music -visit www.jeffreykoepper.com
> 
> 
> 
> 
> **************************************
>  See what's free at http://www.aol.com.
>