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Message

Re: Not getting -5V?

2008-01-14 by Jon

Hi Marcus,

I thought that since the +5V part was working perfectly I'd leave them out.. But i figure it 
wouldn't hurt to change them anyway.

Thanks for the quick reply!

Cheers!
//Jon

--- In korgpolyex@yahoogroups.com, Marcus Wilson <JB@...> wrote:
>
> Hi  Jon
> 
> in my earlier email, I suggest to replace Q1 and Q3 also
> 
> ensure they are the right way around, and see if that helps
> 
> I also gave part numbers for those
> 
> best regards,
> 
> Marcus Wilson
> 
> On 13/01/2008, at 8:19 PM, Jon wrote:
> 
> > Hi!
> >
> > I just got myself another broken Poly-800. (The first one I got is  
> > now beyond repair. As I was
> > offered a second one. I thought: Two minus makes a plus..). But  
> > now, after picking the new
> > one appart. It seems like the -5V circuit is broken. I've replaced  
> > Q18. But the only reading i
> > get is +0.9V where it should be -5V.
> >
> > Could it be that small transformer that's busted? (KD-4? xD-4? It's  
> > hard to read the name on
> > the schematics. And it says T1 on the circuitboard). The output of  
> > it is +0.45V (Measured at
> > leg 1 of D10), I asume it shoudl be -2.50V instead?
> >
> > Any ideas on how to replace it?
> >
> > The long way, I guess, is to replace the entire circuit with a AC- 
> > DC converter that takes 9VAC
> > in and with a 7805 and a 7905 regulates it.. But it seems like to  
> > much trouble right now.. Or?
> >
> > Thanks!
> >
> > //Jon
> >
> >
> >
>

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