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My current Poly six issues

My current Poly six issues

2016-11-23 by mbellomo@vub.ac.be

Hey guys,


First of all thanks for the add in this really insight-full group! 

 I am experiencing some issues with my Korg Polysix: 
Apparently the battery leakage issue on this unit was resolved a few years ago by a Technician which replaced the battery and cleaned up the circuitry underneath... 
The problems I am having are: 
Once I switch to the PWM wave on the VCO there is a weird continuos metallic ground noise (which can be modulated with the filter and Res) ;-)while the 2 other waveforms work normally. 
The VCA / EG / attenuator is not working anymore ( which causes issues with the Enveloppe as well)
The effect part works occasionally... 
The synth is out of tune, I have to play with the pitch wheel and the Intensity to tune it properly (but I guess this is the easiest issues...)

Yesterday I tried to re-upload the patches via Tape and the problem with the PWM Osc kind of disappeared for some minutes but this morning it reappered... 


Could the damages of the battery leakage reappear after some time? I was thinking of buying a KIWISIX card assuming that this would solve all the problems I am experiencing... 
Any hints?



Re: [PolySix] My current Poly six issues

2016-11-23 by Chromatest J. Pantsmaker

Generally speaking, unless the technician did an amazingly thorough job, most "weird" issues (like you have) are directly related to the original battery leakage.  Best thing to do is to open it up and very carefully inspect the circuitboards for anything that looks weird or fuzzy or corroded.  Start around the battery and go outwards from there.  If the ICs haven't been removed and socketed, it's often seen that corrosion is under the chip.  Many "technicians" don't bother to go to this much work.  As soon as it's mostly working, they slap the bill on it and go to the next repair order.

Good luck!

On Wed, Nov 23, 2016 at 8:36 AM, mbellomo@vub.ac.be [PolySix] <PolySix@yahoogroups.com> wrote:


Hey guys,


First of all thanks for the add in this really insight-full group! 

 I am experiencing some issues with my Korg Polysix: 
Apparently the battery leakage issue on this unit was resolved a few years ago by a Technician which replaced the battery and cleaned up the circuitry underneath... 
The problems I am having are: 
Once I switch to the PWM wave on the VCO there is a weird continuos metallic ground noise (which can be modulated with the filter and Res) ;-)while the 2 other waveforms work normally. 
The VCA / EG / attenuator is not working anymore ( which causes issues with the Enveloppe as well)
The effect part works occasionally... 
The synth is out of tune, I have to play with the pitch wheel and the Intensity to tune it properly (but I guess this is the easiest issues...)

Yesterday I tried to re-upload the patches via Tape and the problem with the PWM Osc kind of disappeared for some minutes but this morning it reappered... 


Could the damages of the battery leakage reappear after some time? I was thinking of buying a KIWISIX card assuming that this would solve all the problems I am experiencing... 
Any hints?






Re: My current Poly six issues

2016-11-23 by mbellomo@vub.ac.be

Hey there, 

I think you are actually right! I opened up the Poly and next to the battery (which was indeed changed) you can see some traces of corrosion on the board (guess the technician didnt properly clean the battery leakage...

Do you think that I could completely address this issue by getting ma Kiwisix board? If that's the only way to bring back this baby to a fully functional  state I think I would be ready to spend the 450$ (might have to sell one of my Moogs but it could be an option).... 

Best, 

Michele

Re: [PolySix] Re: My current Poly six issues

2016-11-24 by Chromatest J. Pantsmaker

The kiwisix is a relatively new repair option and I have no experience with it, but I do know that people have been fixing their polysixes for many years. 

I can't say whatever the kiwi will be faster fix, or even if it will be easier.

On Nov 23, 2016 6:43 PM, "mbellomo@vub.ac.be [PolySix]" <PolySix@yahoogroups.com> wrote:


Hey there, 

I think you are actually right! I opened up the Poly and next to the battery (which was indeed changed) you can see some traces of corrosion on the board (guess the technician didnt properly clean the battery leakage...

Do you think that I could completely address this issue by getting ma Kiwisix board? If that's the only way to bring back this baby to a fully functional  state I think I would be ready to spend the 450$ (might have to sell one of my Moogs but it could be an option).... 

Best, 

Michele

Re: [PolySix] Re: My current Poly six issues

2016-11-24 by Florian Anwander

Hello

Am 24.11.2016 um 00:43 schrieb mbellomo@vub.ac.be [PolySix]:
> (guess the technician didnt properly clean the battery
> leakage...
I would not really blame the technician. Cleaning battery leakage is a
tricky job. I have cleaned my polysix years ago and everythin worked fine.
But I also had to clean my Roland CSQ-600 - all trace where blinking
bright copper (I think I have some close up pictures somewhere) and even
under the magnifying glass the traces looked perfectly clean. I did not
replace the battery at that time, but after two or three month I decided
to do so. When I opened the CSQ I found that some traces had thinned out
again a little and some had lifted from the pcb material: appearently
the acid had crept between the copper trace and the pcbs base material
and continued its destroying work there. You don't have a chance to get
it there.

Florian

Re: My current Poly six issues

2016-11-24 by jesusgallego@gmail.com

I ended up swapping my CPU board for a Kiwisix due to too many traces damaged, it was just not worth repairing. Besides I wanted a good MIDI retrofit and Kiwi is just the best. However it I still had to repair some minor damages to fix the PWM and LFO, mainly the MUX chip on the KLM-369. Also had to swap the optocoupler which is pretty typical issue, to get proper tuning scaling. After fixing all the stuff you still have to deal with noise and grounding issues, and with the Kiwisix this worsens quite a bit. There are some nice tips in the Kiwi manual to get rid of some of it but I still have to recap my power board (the two big ones) to further try to reduce it. Anyway, pretty expensive in the end but worth the extensive MIDI implementation and reliability. I'd say it's good investment if you plan to keep your Polysix in good shape for years to come.

Re: My current Poly six issues

2016-11-26 by josh.nursing@gmail.com

Definitely worth it if you can afford it IMO.

I had repaired my KLM-367 and Polysix but I have had some intermittent issues (see the new topic I created) with it, so I think it might some leaked substance continuing to do its damage.

The Kiwisix therefore, naturally came to mind again.

Enjoy!