I just tried it with another 9V DC PSU and the Middle leg of the Q1 connected to the + of the C4 reads 9 . C4 + - reads 0.
--- In korgpolyex@yahoogroups.com, "kjelle.vergauwe" <bobsrampenbedrijf@...> wrote:
>
>
> Between 12.88 and 13.14.
>
> I suspect that it should read 9 :p Hmm.
>
> Weird.
>
> --- In korgpolyex@yahoogroups.com, Martin Ator <cyllall@> wrote:
> >
> > If you measure your 9v power supply do you get 12.88v?
> >
> >
> >
> > ________________________________
> > From: kjelle.vergauwe <bobsrampenbedrijf@>
> > To: korgpolyex@yahoogroups.com
> > Sent: Sunday, 29 July 2012, 12:03
> > Subject: [korgpolyex] Re: Poly 800 MK 1 Short circuit
> >
> >
> > Â
> > I hope I did nothing wrong but here are my results...
> >
> > C3 measures 0
> > C4 measures 0
> >
> > middle leg of Q1 with the +leg of C4 measures 12.88
> >
> > I set my multimeter to 20 V DC. PSU is 9V DC PSU, which still works with other equipment.
> >
> > --- In korgpolyex@yahoogroups.com, Gordon JC Pearce <gordon@> wrote:
> > >
> > > On 29/07/12 10:32, kjelle.vergauwe wrote:
> > > > I'm not really good with a multimeter, but....
> > > > Just tested the Diode. I'm measuring 587 and 1. No beep though.
> > >
> > > A "1" in the left-most digit of the display? That means "infinite".
> > > Those readings look pretty healthy.
> > >
> > > > Also noticed when measuring that the wires from the diode are black, I could scrape black dust off of it. (see picture)
> > > >
> > > > http://dl.dropbox.com/u/7760238/poly%20800/Diode.JPG
> > > >
> > >
> > > That's just the plating getting oxidised, it's normal.
> > >
> > > Refer to page 1 in the diagrams I linked to in my previous post, bottom
> > > left corner.
> > >
> > > With the AC adaptor plugged in and the power switch on, measure the
> > > voltage across C3 (little disc ceramic capacitor) or C4 (one of the
> > > three electrolytics near there). You should see about 9V. If not,
> > > measure the voltage between the positive side of C4 and the middle leg
> > > of Q1 (2SB744). You should see whatever voltage the PSU is putting out.
> > >
> > > You may need to remove Q1 from the board to test it, but I bet that's
> > > what the fault is. If you're not comfortable with soldering and
> > > desoldering, then find some friendly neighbourhood electronics geek to
> > > help you ;-)
> > >
> > > --
> > > Gordonjcp MM0YEQ
> > >
> >
>