[sdiy] Need help reading a schematic

[Peter Pearson]

Do you have a multimeter?  You should really go through and measure things
before replacing parts.  Best practices.  Make sure to unplug it from the
wall first ;)

This Dynacord service manual has a power supply in it (page 30) and is
probably similar enough to compare to the circuit you're looking at:

http://www.synfo.nl/servicemanuals/Dynacord/DRS-78_SERVICE_MANUAL.pdf

As an aside, I have seen the bridge rectifier go bad on Dynacord stuff more
than once.

On Thu, Aug 13, 2020 at 8:48 AM Ben Stuyts <ben at stuyts.nl> wrote:

>
>
> > On 13 Aug 2020, at 09:43, Jean Bender <lofideadbeat at gmail.com> wrote:
> >
> > As 2 fuses always blow up if powered, i'm pretty sure the power
> > transformer is dead, it's not a thoroidal one. I gonna try to get a
> > 220V to 2 secondary 18V AC and see if it lett the pdd14 can go back to
> > life ;).
> > The regulators are LM7815, 7915 and 7805.
> > The only thing i don't get yet is that two wires go from one
> > secondary, the V+ one goes through a fuse and then directly to the
> > pedal board jack. I guess i don't need it actually, as i don't have
> > the pedalboard !
>
> Something doesn’t add up. Are both those two fuses both on the secondary
> side? If so, what makes you assume the transformer is bad? Have you
> actually measured the output voltage of the transformer?
>
> If anything, that would point to a problem further on.
>
> Ben
>
>
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