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Trying to identify and locate component or suitable replacement

Gary Hodgson

Nov 28, 2016
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Hi -
I am in process of repairing a synthesiser called Korg MS2000. It wont power on. It is powered by a 9v dc wallwart. I have identified the cause of the problem as a short circuit across the + & - and the source of this is I think a double coil (labelled M522C - L11 in diagram).The problem I have is locating the component M522C - I am assuming it is a coil? dont know value, rating or indeed what it is doing there - is there anyone out three who can help - i am a qualified Electronics Technician but am a little rusty having been out of the business for 30 years! Please see photo and diagram - Thanks Gary
 

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duke37

Jan 9, 2011
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There are some components shown on the diagram which are shorted. I think these may be optional and, if used, the links should be removed.

There are lots of connecting points which are not used. I would suggest that M522C is not fitted and so would not cause a short.
 

Gary Hodgson

Nov 28, 2016
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thanks for the reply Duke - the thing is though, this was working as you see in the pic - the circuit diagram includes L10 & L12 which as you say arent in the pic - I think this might be an either/ or circuit dia though there is nothing on the diagram that suggests this. (Japanese?)
Since I put this post up I have managed to locate a 'common mode choke" one of these TDK ZJYS51R5 i think this is what I need - I will let you know how I get on
 

davenn

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Sep 5, 2009
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I think a double coil (labelled M522C - L11 in diagram).The problem I have is locating the component M522C

what do you mean you cant locate it ?? it's labelled on the board as L11 and has 8Y on the top of it

it's a twin coil as can be seen from the circuit diagram there will be a short circuit across pins on either side of the coil eg

upload_2016-11-29_6-53-51.png

and the same for the 2 pins on the other side
there should be no short between the 2 pins at each end of the component



I would suggest that M522C is not fitted and so would not cause a short.

no, that is incorrect ... you can see it in the pic
 

73's de Edd

Aug 21, 2015
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There are several . . . Normally Unused . . . components on the board and one at the top right corner that cannot be made out.
There is an option of using the combined bifilar choke or individual chokes on both legs of the power supply feed lines.
Also there's an option of using an extra diode for current boosting.
And further on down the supply path , there can be a choke and a series electrolytic capacitor to ground.

73's de Edd
 

duke37

Jan 9, 2011
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I did not recognise 8Y as a common mode choke. There will be a connection between top and bottom but no short.

C25 looks to have a domed top and could be the source of the short. Also investigate C35.
 

Gary Hodgson

Nov 28, 2016
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what do you mean you cant locate it ?? it's labelled on the board as L11 and has 8Y on the top of it

it's a twin coil as can be seen from the circuit diagram there will be a short circuit across pins on either side of the coil eg

View attachment 30532

and the same for the 2 pins on the other side
there should be no short between the 2 pins at each end of the component





no, that is incorrect ... you can see it in the pic

i mean i cant locate a manufacturer!...one to purchase......there is a short across pins on both sides with it removed from the board so it is us yes - do you know the value of this dual coil dave??
 

davenn

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do you know the value of this dual coil dave??

sorry, offhand, not sure ... it's just a noise filter, the value wont be wildly critical

so out of the circuit, you are getting a short between the close together terminals ?
 

cjdelphi

Oct 26, 2011
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Yup that "short" is normal after all it is just a coil of wire...

Got a photo of the board?
 

davenn

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Yup that "short" is normal after all it is just a coil of wire...

Got a photo of the board?

BUT NOT between the 2 close ends

LOTS of photos up the thread please read all thread before commenting ;)
 

Gary Hodgson

Nov 28, 2016
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sorry, offhand, not sure ... it's just a noise filter, the value wont be wildly critical

so out of the circuit, you are getting a short between the close together terminals ?

Yes....Ive ordered one of these - TDK ZJYS51R5 - arriving today - ill let you know - thanks
 
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