[sdiy] broken oberheim matrix 6r

[Doug Terrebonne]

No I'm in the SF Bay Area... Just saw it on ebay is all... I have a
fully working 240 so it might be cool to get...


--- Bob Weigel <sounddoctorin at imt.net> wrote:

> Yeah sometimes that is the best way.  If you are in a real hurry  and
> a 
> board is hard to get out...hehe..you might take sharp nips and cut
> the 
> pins leaving most of it sticking up.  Toss the old chip then flux the
> 
> new ones and pretin.  Flux again then melt each onto the pins
> quickly.  
> If it has to be done..in 10 minutes :)
> 
> I haven't personally seen the chips fail.  But always a possibility. 
> 
> Often several of them are used in some kind of scheme since they have
> 
> limited outputs.  So get the diagram for one and start testing to see
> if 
> all the outputs are doing something reasonable.  There could also be
> two 
> cpu's in those I can't recall.  In the kawai of similar design
> (SX240) a 
> power supply issue took out the cpu, and an old ssm narrow package
> 6116 
> memory chip and possibly another that I replaced before I got there. 
> 
> What a pain that was. But that would allow all the patches to be 
> editable etc. but no sounds of course since that cpu system handled
> the 
> oscillators -Bob
> 
> David Brown wrote:
> 
> > I had an 8253 fail in my Matrix-1000 which is basically the same 
> > circuit design.  Two data pins shorted together with ~100 ohms.  
> > Totally screwed up the processor.  I had to shotgun cutting data
> lines 
> > to figure out where the short was.  The good news is that the 8253
> is 
> > cheap and available but a bear to replace.  I ended up cutting off
> all 
> > the pins and removing each pin individually with a solder sucker.
> >
> > Dave
> >
> > At 12:46 PM 4/4/2007, Danjel van Tijn wrote:
> >
> >> Hi karl,
> >>
> >> Does the 8253 timer commonly fail? I will definitely check it
> out...
> >>
> >> thanks for the tip!
> >>
> >> Danjel
> >>
> >> On 4/4/07, karl dalen <dalenkarl at yahoo.se> wrote:
> >>
> >>> Have you checked the 8253 timer?
> >>>
> >>> If these dont work you wont get any sound!
> >>>
> >>> KD
> >>
> >
> > _______________________________________________
> > Synth-diy mailing list
> > Synth-diy at dropmix.xs4all.nl
> > http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> >
> >
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>