Korg Poly800/EX800 Users

the original email said that the voltage was still 13 volts while plugged in to 
the Poly.




________________________________
From: backshall1 (dsl) <backshall1@...>
To: korgpolyex@yahoogroups.com
Sent: Sun, December 26, 2010 10:24:41 PM
Subject: RE: [korgpolyex] Re: korg poly 800 power problem

  
A newer switching supply wall wart will give you a  consistent 9vdc regardless 
of current flow, but an older one with a big  transformer will be 12-13 volts 
when there isn't much power being used, and drop  to 9v when you are using the 
rated current. I've used ones that measure 12-13  volts without any problems.
 
Don B.


________________________________
 From: korgpolyex@yahoogroups.com  [mailto:korgpolyex@yahoogroups.com] On Behalf 
Of korgpolyex800
Sent: Sunday, December 26, 2010 9:58  PM
To: korgpolyex@yahoogroups.com
Subject: [korgpolyex] Re:  korg poly 800 power problem

  


The wall wart should be providing a consistent 9V DC  output.

If you're seeing 13 volts at the input of the Poly 800 then you  need to get a 
9V DC wall wart. 13 volts will overload the on board power supply  control 
circuits.

Mike

--- In korgpolyex@yahoogroups.com, "n8"  <natere2ster@...> wrote:
>
> hi list.
> 
> just  joined and have a question perhaps someone can chime in on...
> 
> i  have a korg poly 800 mkI here on the bench with a power issue.
> 
>  when on batteries it runs fine, but will not run off the wall wart...
> 
> the wall wart works ok, i tested the voltage on the dc plug and it is  spitting 
>out 13V const. I read that at the DC jack as well...
> 
>  The problem so far looks like i do not get the +5V on the connector CN06A on 
>pin  10....is that correct?
> 
> I get the pull DC in on pin 11 so that  is good!
> 
> But i need to get that 5V on pin 10 so it can be sent  to the chorus board, 
>then to the volume / switch on?
> 
> from the  rough schematics i see that Q1's base and collector are tied to this 
>rail, and  its emitter is tied to the DJ jack....
> 
> Q3 is E-C is on the 5V  line, and its base is tied to Q2 tranny which is tied 
>to Q15 which is tied to  gnd.
> 
> Is this correct?
> 
> I assume its one of the  power switching transistors are bad, how can I confirm 
>this? I de-soldered Q1  and have it on the breadboard.
> 
> I used the standard transistor  PNP tester circuit, as seen here:
> 
> http://www.kpsec.freeuk.com/trancirc.htm
> 
> It seems to work fine, I can turn the led on when the switch is closed  and 
>turn it off when its open...
> 
> So i guess its ok and i should  put back LOL?
> 
> Anyone know of any other transistors to  check?
> 
> I am looking at Q3 for some reason....
> 
>  What steps down to voltage from the DC jack in out to the +5V?
> 
>  I assume once i get the +5V i will be ok...
> 
> i just keep looking  at Q1 and Q3 cause they are both tied into GND, the DC 
>jack in, and the +5V  rail.....
> 
> Sorry for all the questions i am noob!
> 
> Cheers,
> 
> Nate
>