[sdiy] Broken CR-78

[Rude 66]

chad,

 i think you've been noticed by more.. just not ones with the anwer to the
question..;-)

it certainly looks like that's where the wire goes. you can check and see
where the trace that leads to this connection, goes to. if this wire is
indeed the 'master grounding' for the machine, all sorts of idiotic
behaviour can come from the ic's.
i'm only a little bit farther
up the diy ladder than you, but 99% of all problems that i have encountered,
especially on older machines, have to do with loose wires, bad solder
contacts and/ or shitty connectors.  the recipe that helped me with several
machines was first, clean the inside, then clean all the connectors and
gently push on all the ic's that are in sockets.. then if that doesn't work,
find out which board is most likely to be the problem, and resolder all
connections. it's a pain, but for me it's fixed several machines so far.
ymmv.

r./






----- Original Message -----
From: "Chad Coffman" <chadcoffman at comcast.net>
To: "diy synth" <synth-diy at dropmix.xs4all.nl>
Sent: Monday, June 06, 2005 8:25 AM
Subject: Re: [sdiy] Broken CR-78


> Ah, ha! Somebody has noticed me!  :-)
>
> Thanks for the link.
>
> I'm ignorant of these things, but I don't think it's the power supply,
> considering the unit powers up and all. The multimeter is in the mail, so
I
> can't test it just yet (I'm merely beginning my crash-course). In the
> meantime, do you suppose it would cause any harm to move that purple
ground
> wire back to where it should go--assuming that is where it was originally
> intended to be?
>
> Say the ground wire *was* moved to its present location sometime before
the
> unit came into my possession, what possible effect could it have?
>
> I'll have a look at the output audio circuit come daylight --supposing I
can
> find it :-)
>
>
> --Chad (quite literally sleepless in Seattle)
>
>
> ----- Original Message -----
> From: "KA4HJH" <ka4hjh at gte.net>
> To: "Chad Coffman" <chadcoffman at comcast.net>
> Cc: <synth-diy at dropmix.xs4all.nl>
> Sent: Sunday, June 05, 2005 10:37 PM
> Subject: Re: [sdiy] Broken CR-78
>
>
> > >I uploaded a pic of the aforementioned ground wire if anyone is
> > >interested
> >>in seeing what I'm talking about. It can be viewed here:
> >>
>
>><http://home.comcast.net/~chadcoffman/cr78.jpg>http://home.comcast.net/~ch
adcoffman/cr78.jpg
> >
> > Interesting. The schematic is here:
> >
> > http://www.etek.chalmers.se/~e5he/engindex.html
> >
> >
> > Obvious things to check--power supply, output audio circuit (could have
> > been zapped by plugging it into the wrong thing).
> >
> > --
> >
> > Terry Bowman, KA4HJH
> > "The Mac Doctor"
>
>