Thank you for your answer Taylor
Ok i'll remove my 2 mod toggle switches. The second one is the optionnal 10uF cap, anti-ticks, which i putted on a switch. ( i didn't know if i would keep it or not)
I'd carefully checked continuity on the 2P6T before everything, and i can confirm how it's routed :


Blue wires are A1&B1 (pcb 2&7), green A2&B2 (pcb 3&8 ), Yellow A3&B3 (pcb 4&9), orange A4&B4 (pcb 5&10), red A0&B0 (pcb 1&6)
As you see,i putted jumpers over lug 4-5-6 on A, and B, to avoid dead positions on the rotary switches. So, square wave should be over position 4,5 and 6.
i assume that's i have been meticulous on this, and when i check continuity, over different lugs when it's wired, it makes sense regarding the rest of the circuit and the rotaru switch position.
I have a doubt on the FET, as i don't know how to test it, and how it should react, or give information on scope or not.(i'm still a noobie...)