I think a few keys may have worked on mine when I got it but not many. If you can short rows to columns and get notes, then the key contacts are not working. You can read the resistance of the key contacts by simply unplugging the cable and using a meter. Row 0 column 0 is the bottom key, then col 1, 2, etc. the second group of eight keys use row 1.
Try cleaning first. Its cheap and might work. Only certain keyboards seem prone to this particular failure mechanism.
Bob
From:
mpe1969@tpg.com.au [PolySix] <PolySix@yahoogroups.com>;
To:
<PolySix@yahoogroups.com>;
Subject:
[PolySix] Re: polysix still no sound
Sent:
Fri, Nov 21, 2014 1:35:43 PM
Thanks. I've been looking at the schem. I assume the key scanning is working correctly. Eg the appegiator would not work. Is it very common for all key contacts to fail? Thanks again
2014-11-22 by mpe1969@tpg.com.au
I had a look at the contacts today. The problem is the rubbers. I have bought some conductive paint to try. If this fails I will go for the replacement disk option. Today I did two coats which fixed half of them. The rest I have repainted right up to the sides. Hope it works.
I've notice another problem my effects pot seems to also act like a volume. I suspect the pot is faulty.
So good to be getting some sounds out of the keyboard!
2014-11-22 by chipaudette@yahoo.com
I used CaiKote to rejuvenate the key contacts on my Mono/Poly and on my Polysix. Worked like a charm.
Chip
2014-11-23 by mpe1969@tpg.com.au
Well after moving my rubbers around on the keyboard I realised that the problem was the pcb keyboard pads not the rubbers. I initially cleaned them with alcohol. After going back over them all with an eraser ALL my keys work. Super!
I still have to work out what is happening with my effect. All of them work however the speed potentiometer works like a volume at the same time, e.g. no sound until about 11 o clock then the volume and speed begin to increase. On the 'no effect' setting it acts as a volume. If anyone has any thoughts? My battery leak did get up onto this board, but all other functions seen to be working correctly
Once again thanks everyone for helping out. So great to have the assistance, keeping the polysix alive!
2014-11-24 by mpe1969@tpg.com.au
My effect ifs fixed. I'm writing this in hope it may help someone else out with a similar problem. First I check the speed potentiometer with multi meter. This showed 5- and 5+ on the outside legs and a swing in-between on the centre leg when the potentiometer was turned. (so this was ok). I then pulled out the effect pcb. The battery leakage had gone under neath this board as well. I cleaned up all the tracks and replaced the Electro caps in this vicinity. After this I tested it out and......she works!
....that battery leakage....
2014-12-05 by mpe1969@tpg.com.au
My effects are still playing up. It worked for about a day then went back to the initial problem. If I do a fast tiani clockwise turn on the speed pot I lose all sound for a few seconds then it fades back in quietly. The speed pot still seems to increase volume when turned (speeds effect) I have cleaned the speed pot again and am getting correct voltage. I have checked pin 7 (speed from klm 367) and it is transmitting voltages. I have checked the voltage on ic 19 pin 1 and it sways up to 14 v when the speed pot is turned. Pin 7 of ic 19 Changes from 4 to 8v. Pin7 of ic 18 swings from 14- to 14+.
I'm not sure what to test next. Thanks
2014-12-06 by mpe1969@tpg.com.au
A well today I recapped most of the effect pcb (the 'brain' part of the board.) when I reconnected, the effect speed pot seemed to control the resonance, cutoff and volume. Then after a few power off and ons it went back to the initial problem. I will add the the volume is extremely loud in the headphones, I can't turn it passed 1 when the effect pot is fully turned clockwise. If anyone has any advice I'd appreciate it as I'm a little lost as what to test next (eg ne571?)
Thanks again
2014-12-06 by Dennis Matana
Hi,
First do you get sound from the oscillator board? Its the two white wires that are going to the fx board.
After the fx board the signal goes to the pcb which holds the volume pot. There is also an op amp and from what iom reading maybe that opamp is bust. Mine was and i had similar problems.
Also check if datalines D0 till D7 are reaching their pull up resistor network which is placed bewteen the cpu and ic31. If the dataline is not pulled up the p6 will get confused.....
good luck
On Saturday, December 6, 2014 7:23 AM, "mpe1969@tpg.com.au [PolySix]" <PolySix@yahoogroups.com> wrote:
A well today I recapped most of the effect pcb (the 'brain' part of the board.) when I reconnected, the effect speed pot seemed to control the resonance, cutoff and volume. Then after a few power off and ons it went back to the initial problem. I will add the the volume is extremely loud in the headphones, I can't turn it passed 1 when the effect pot is fully turned clockwise. If anyone has any advice I'd appreciate it as I'm a little lost as what to test next (eg ne571?)
Thanks again
2014-12-07 by mpe1969@tpg.com.au
Thanks I get sound from the oscillators. I tried replacing the headphone op amp today but it didn't change the volume issue. I did some recapping and pot cleaning while the boards were out.
I'm at a stage where all effects are working and the speed control works but it also reduces the volume when turned anti clockwise. I can keep it around half way to keep it working. Weird. Remarkable the sounds that come the poly though. Super filter and the auto chord function is great.
2014-12-07 by Dennis Matana
ok so maybe somewhere down the audio line there maybe is a loose connection? Have you checked the wiring going from the fx board to the frontpanel pcb? Korg is known for bad connectors...in my old P6 i also reflowed all solder joints of the connectors...also check the pcb tracks on the front pcb, ive had some bad tracks on those
good luck, br Dennis
On Sunday, December 7, 2014 4:47 AM, "mpe1969@tpg.com.au [PolySix]" <PolySix@yahoogroups.com> wrote:
Thanks I get sound from the oscillators. I tried replacing the headphone op amp today but it didn't change the volume issue. I did some recapping and pot cleaning while the boards were out.
I'm at a stage where all effects are working and the speed control works but it also reduces the volume when turned anti clockwise. I can keep it around half way to keep it working. Weird. Remarkable the sounds that come the poly though. Super filter and the auto chord function is great.
2014-12-30 by nmr2@rocketmail.com
It difficult to know where in the audio path is the culprit.
also, heres a clearer audio probe schemo
2016-02-07 by jw_dewdney@yahoo.com
mpe19696 - can i ask what you meant by 'less lit up' (as each patch loaded)? I am only asking because - after having hooked up my replacement KLM367 board, everything is disabled seemingly- and all the lights on the front panel are on... and I'm just wondering if yours was in a similar state when you started up... before loading any...
