Elektor Formant Modular

I have now tried to fix this problem but no luck yet... 
I cannot measure the voltage of the mcv4 but I tried it with my korg ms-20 (wich  has a 5v 
gate if I remember correctly) and it works fine.
I have opened the back and soldered an gate input by connecting the gate and ground from 
the synth to a cable that goes to the mcv4, and it doesn`t work, and it is not he cable, I`ve 
tried 3 different ones. The weird thing about this is that the gate works perfect if it`s played 
by the keyboard. Can it be that this particular elektor formant has a higher gate voltage?
I have also tried all this with my kenton pro solo.

-Wille