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
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