Discussion about the Korg PolySix synthesizer

Hi everybody,

I'm quite desperate here, so I hope someone could help me a bit especially because I'm not very good in English and I'm not an electronic guy!
A couple of years ago I found a polysix which had the famous leak battery problem, so impossible to play on it.

I tried to repair the KLM 367 but with no success. 
Then i discovered the Jed's project

Today I've just finished to solder all the parts on the KLM-367A clone board.
I put the board back on my P6. Then I turned it on.

First, the programmer panel seems to work fine, Led button repond when I push them

BUT there is no sound at all. Just some attack sound, some 'blops'.

When I hold a key down, I can hear the note coming very slowly and fade out. Just like the LEd of the MG panel fading In and Out very slowly.

The Mg frequency, delay and level's knobs don't affect the modulation. Even if the modulation level is at 0, the sound is fully modulated

So I guess it's the MG section which seems to not work properly. It looks like it is stuck on a very slow frequency and there is no way to cut the modulation.
 

Also cutoff, resonance, eg int, keyboard track knobs don't seem to change the sound.

When I built the new Jed's PCB, I used from the old board the mask rom IC, the TC5514APL-3 IC, the two LM13600 ICs and the 2SA798

What do you think? Is it possible that one of the Ic is dead? Or does it look like the problem is deeper?

Please excuse my poor english !


Cheers!

Vincent