Polysix and effect loss problem - HELP

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radek tymecki
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Polysix and effect loss problem - HELP

Post by radek tymecki » Mon Dec 31, 2007 1:10 pm

Hi there

Yesterday there were some problems with power supply and my Polysix lost Ensemble effect :( Phaser and Chorus works fine but when I switch effect to Ensemble the signal on the output is unprocessed... What can be the reason? Dual OpAmps on effect board?

help
thanx

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Post by mao » Mon Dec 31, 2007 1:50 pm

I think you checked your battery... to see if it has the famous polysix problem... It does strange things. A friend of mine after 10 minutes loses all the sounds...

Check if the battery has lost acid on the mainboard erasing some connections.

http://www.oldcrows.net/~oldcrow/synth/ ... epair.html

http://analog.no/mods/korg_polysix_battery_leakage.htm

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Post by Jexus » Mon Dec 31, 2007 4:02 pm

... and there shall come the time where all your analog synths start dying one after another... and thou canst do nothing to stop it...

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Post by radek tymecki » Tue Jan 01, 2008 5:44 pm

No battery leak ;)

It was changed some time ago

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Post by Maschinengeist » Wed Jan 02, 2008 8:41 am

http://www.oldcrows.net/~oldcrow/synth/ ... p6smm7.pdf

Here's the schematic for the KLM-368 Effect board.

I'd start testing the LM324N (IC23) and check it against the datasheet: http://pdf1.alldatasheet.com/datasheet- ... M324N.html

That would be a start... assuming the switch is ok.
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Post by radek tymecki » Wed Jan 02, 2008 11:55 am

Yea. Probably I'll exchange lm324n and opamps on bbd's 1-2-3

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Post by radek tymecki » Thu Jan 03, 2008 11:34 pm

Maschinengeist wrote:http://www.oldcrows.net/~oldcrow/synth/ ... p6smm7.pdf

Here's the schematic for the KLM-368 Effect board.

I'd start testing the LM324N (IC23) and check it against the datasheet: http://pdf1.alldatasheet.com/datasheet- ... M324N.html

That would be a start... assuming the switch is ok.

I've exchanged those parts still with no result :(

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Post by radek tymecki » Fri Jan 04, 2008 12:28 am

I've checked the effect board on other Polysix. Works OK

So what's wrong then?

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Post by Europe Endless » Sun Jan 06, 2008 9:41 pm

If the effect board is working properly in another P6, the problem must be either on the KLM-367 board or on KLM-370. I´d put my money on the KLM-367.
Lets first establish if it´s a input or output problem. The “ensemble” position on the effects switch is read by the microprocessor through lines DO2 and P13. First check P13 by selecting pressing bank select “D” and then presets 4 and 8. If you can select those then P13 is OK. Next, check DO2 by pressing preset 3 and then bank C. If the corresponding LEDs light up then DO2 is OK. Next, check the DO2 and P13 lines to the KLM-370 by toggling the “EG mode” switch and also testing if the three last positions (+4,+8,+10) on the attenuator switch work. If these tests are OK than the “input” part is fine.
The CPU outputs the signal to turn “ensemble” on via DO3 through the latch IC34. Check DO3 by pressing preset 4 and bank select D. If the LEDs light up properly, then DO3 is OK.
If you´ve gotten this far without a hitch, I´m willing to bet that the problem is the CMOS latch IC34. If some of the above tests failed, it´s highly likely that you suffer from previous problems of battery leakage. DO2 and DO3 are buffered by IC31, which is the chip closest to the battery, and the traces beneath are most prone to damage by battery acid. Remove the KLM-367 and use an ohmmeter and the schematic to check the connection from every pin on IC31 to the rest of the circuitry.
There is always the possibility that the rotary switch itself is faulty, but I´d leave that to last.

Good luck!

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Post by radek tymecki » Mon Jan 07, 2008 12:09 pm

Yo

Just forgot to tell that I solved problem few days ago :)

Anyway thx 4 helpin me :)

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Post by Synthaholic » Mon Jan 07, 2008 2:13 pm

So, what did you do to fix it?
Two VCO: thanks to the push rods, one can choose several forms of waves at the same time!
(from a Babelfish translation of a Jupiter-6 site)

Yamaha: Motif XS6, TX802 Roland: D-550 Alesis: A6 Andromeda

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Post by Europe Endless » Mon Jan 07, 2008 4:15 pm

Synthaholic wrote:So, what did you do to fix it?
Exactly - was I even close? :)

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