This power indicated as "Extra power 3" must also be from PSU1.
Otherwise the connection is ok, I have this as well.
I think so too, but I have to be sure. I don't want to risk this anymore, it's scared me to see my equipment burn up and potentially burn down my house :sOtherwise the connection is ok, I have this as well.
Similar thing happened to me, but luckily I have seen the damage on my PSU cabal before it has started the fire. What went wrong for me was that, I put too many GPU's on one PSU. Because of that, there was too much stress on PSU's wires, which lead to damaging of wires. Maybe you have same problem. Maybe your PSU is not strong enough to support those 12 GPU's that you have.
I'm using 2x Corsair RM1000x PSUs of 1000W a piece. 6 GPUs are on PSU1, 6 on PSU2 