Vintage Synth Repair

have you taken a look here: https://www.gearslutz.com/board/electronic-music-instruments-electronic-music-production/721112-oberheim-ob8-how-make-survive-next-10-more-years.html


have you tried to inspect for possible pcb leaks

From: mailto:vintagesynthrepair@yahoogroups.com
Sent: Saturday, June 18, 2016 8:41 AM
To: vintagesynthrepair@yahoogroups.com
Subject: [vintagesynthrepair] Oberheim OB-8 with no hope?



Dear all,


Here in Norway we have an Oberheim OB-8 that several people including me had been trying to make work, without any progress.
Power supply upgraded (new power regulators, new caps), all of the old CMOS chip replaced, new EPROMs, a lot of the opamps and stuff replaced, caps replaced, cables, connectors and voice-cards checked (all analog voices seem to work), but no matter what - it does not operate properly at all. It boots, LEDs light up, and there is some random response from the keyboard, but there is no proper control of anything, and the sounds coming out as result of various boots range from analog noise, highpitched digital noises, various uncontrolled lowpitched growls from the analog voices and the like. I was able to get some control in the end, like turning analog noise on and off, haveing the envelopes response somewhat (timevise), and a little bit of filter cutoff and resonance responds (those time the analog voices came on). Obviously, all check-points, calibration, digital lines and voltages have been controlled many times, and are all perfect, but still no go for this instrument. To me it seems that the digital system of this machine is completely busted.
Interesting enough, I have noticed that some vintage service shops (even in the USA) have announced that they no longer service OB-8, only all other Oberheims.


So: any feedback or response regarding this are appreciated.
- Should we just give up and sell this as a parts machine (everything physically is 100% intact)?
- Should we announce this as a really challenging repair object for sale?
- Or are there anyone out there who is willing to and have the deep knowledge to service this instrument?






Terje Winther
terje.winther@wintherstormer.no
http://wintherstormer.no/

Thank you very much for this. Very inspiring.
Yes, I have done almost everything it says in the post.


Terje




Den 20. juni. 2016 kl. 00.24 skrev Cosmic Fugue cosmicfugue@...
[vintagesynthrepair]:


>
> have you taken a look here: https://www.gearslutz.com/board/electronic-music-instruments-electronic-music-production/721112-oberheim-ob8-how-make-survive-next-10-more-years.html
>
> have you tried to inspect for possible pcb leaks
>
>
>
>
> From: mailto:vintagesynthrepair@yahoogroups.com
> Sent: Saturday, June 18, 2016 8:41 AM
> To: vintagesynthrepair@yahoogroups.com
> Subject: [vintagesynthrepair] Oberheim OB-8 with no hope?
>
>
> Dear all,
>
> Here in Norway we have an Oberheim OB-8 that several people
> including me had been trying to make work, without any progress.
> Power supply upgraded (new power regulators, new caps), all of the
> old CMOS chip replaced, new EPROMs, a lot of the opamps and stuff
> replaced, caps replaced, cables, connectors and voice-cards checked
> (all analog voices seem to work), but no matter what - it does not
> operate properly at all. It boots, LEDs light up, and there is some
> random response from the keyboard, but there is no proper control of
> anything, and the sounds coming out as result of various boots range
> from analog noise, highpitched digital noises, various uncontrolled
> lowpitched growls from the analog voices and the like. I was able to
> get some control in the end, like turning analog noise on and off,
> haveing the envelopes response somewhat (timevise), and a little bit
> of filter cutoff and resonance responds (those time the analog
> voices came on). Obviously, all check-points, calibration, digital
> lines and voltages have been controlled many times, and are all
> perfect, but still no go for this instrument. To me it seems that
> the digital system of this machine is completely busted.
> Interesting enough, I have noticed that some vintage service shops
> (even in the USA) have announced that they no longer service OB-8,
> only all other Oberheims.
>
> So: any feedback or response regarding this are appreciated.
> - Should we just give up and sell this as a parts machine
> (everything physically is 100% intact)?
> - Should we announce this as a really challenging repair object for
> sale?
> - Or are there anyone out there who is willing to and have the deep
> knowledge to service this instrument?
>
>
>
> Terje Winther
> terje.winther@...
> http://wintherstormer.no/
>
>
>
>
>
>
>


Terje Winther
terje.winther@...
http://wintherstormer.no/

Thank you for the link, will check up on that.


Terje




Den 20. juni. 2016 kl. 11.58 skrev alfco@... [vintagesynthrepair]:


> My Oberheim obxa had a similar problem and the CPU was broken. It
> has been checked in the Netherlands, but they could not find the
> problem. In the end I brought my obxa to Germany Oberheim Mellotron
> Novatron Simmons Kurzweil
>
>
> Oberheim Mellotron Novatron Simmons Kurzweil
> Erfahrungsberichte, Tipps, Technik, zu Mellotron, Novatron,
> Oberheim, Simmons, Kurzweil, Midi-Controller
> View on www.blue-jet.de
> Preview by Yahoo
> and he is very nice and could fix my obxa.
>
> Please try to change the CPU at first.
>
>


Terje Winther
terje.winther@...
http://wintherstormer.no/