Thanks for the comments guys.
I have just bought a new 4pm. I was doubting between the Futaba 4pm, Sanwa Mt 5 and flysky Nobel nb4. After seen much reviews I choose the futaba. The Nobel is very nice but I can't accept the death zone and angle difference when steering.
Good choice?

But I have my 3pk completely taken apart now. As technical guy like you are, i can't put it into the bin and forget it.. With the spektrum and the new corona module and reciever it doesn't matter about the range, both are poor. So the problem has to be inside the pistol or connection between the module and pistol. I can't see anything wrong or black stuff on any pcb. Futaba doesn't give any electric schedule or wiring colors. I was hoping someone can help me with this or other advice before I completely trow it away 🤣
Thanks