Vintage Synth Repair

Hi,

I removed the coating on the original 80017 chips by soaking them in acetone. It took about a week to completely remove the coating.

I reinstalled the chips in the Juno-106 and them seems to be working fine now. I'm gonna test them for a couple of days to see if they don't fail again.

The only thing I would advise is not to remove the small pins on these chips like I did. I was able to resolder them but not without damaging the pads on the board. They seems to be fragile.

Thanks for your help!

Nicolas



--- In vintagesynthrepair@yahoogroups.com, "hughvartanian" <bouncev@...> wrote:
>
> I rebuilt a 106 recently and cleaned the chips so you needed sunglasses to look at them, even under most all of the IC pins.  Still, I had some leakage on a couple of channels.  While I cannot find the schematics now, I remember that I found the input to the VCA and using some 100K - 200K range resistors, perhaps to V+ but maybe ground (don't remember!), I managed to bring the amp back to just the point of cutting off and stopped the leak-through.  I remember selecting the highest resistor that would stop the leakage on each channel with the problem.  I recall that I got to this by measuring the voltages on the control pins to the 80017A, although I also recall that they might be current-controlled inputs.
> 
> If you need me to dig into the schematics and chip block diagram I can maybe provide some more detailed guidance, although I do not have the synth anymore to confirm any story I might be telling from memory!
> 
> I purchased an 80017A from synthparts.com  (email synthparts@...). Doug was the guy's name. Service was fine enough.  (I can not say if the part I got from them had the leakage problem or not since I did not keep track of that one vs. the other 5 in my 106.  There were 2, maybe 3 parts that I had to make this mod to when I was finished re-assembling everything.)
> 
> Good luck,
> Hugh
> 
> --- In vintagesynthrepair@yahoogroups.com, Terje Winther <terje.winther@> wrote:
> >
> > Yes, they are still around.
> > A bit slow business, but very good products.
> > 
> > 
> > Den 7. april. 2013 kl. 17.26 skrev Nicolas:
> > 
> > > Hi,
> > >
> > > I used to order some 80017A chips for the Juno-106 from Analogue  
> > > Renaissance because they are great and reliable.
> > >
> > > But recently it seems very difficult to contact them by email to  
> > > make an order. The didn't replied to my last emails.
> > >
> > > Are they still in business?
> > >
> > > If no, is there an alternative
> > >
> > > Thank you!
> > >
> > > Nicolas
> > >
> > > 
> > 
> > Terje Winther
> > terje.winther@
> > http://wintherstormer.no/
> >
>