XXHighEnd

The title shows strange but this is a serious warning for those who think that the black (ground) wire coming from the USB Interface and ending up at one of the bolts (screws) at the main PSU in the right leg - can just go out for trials.

NOT.

I say this because I have noticed that people (might) think that this wire can be removed regardless. NO. It can only go when at the PC end the USB interface is isolated from the PC chassis;
Not need to explian *that* in here, if it is only clear that nobody should remove that wire while at the PC end nothing has been done about actually the same wire which relates to PE (Protective Earth).
Be sloppy about this and some USB Interfaces may start smoking ... (blow up).

Notice that the other way around is allowed : Isolate at the PC side but leave all in order inside of the NOS1. However, this too is not a consistent situation and it better not be done like this.
Both sides "isolated" is OK, and both sides attached is OK too.

In all cases you are responsible yourself of course with the notice that when something goes wrong you will not be on your own. But it may cost you a few $$.

Peter

In addition because it is VERY easy to make the mistake :

So suppose you have both sides isolated and next you want to compare in quick fashion with your MoBo USB connection (instead of the USB3 PCIe interface).

Don't.

It obviously implies the same situation as described above.

Peter

I wonder if leaving the black wire attached and putting a resistance on it could have a positive effect ?

Alain

PS: If I understand correctly (if...): putting a resistance will not allow the easy flow of a different electrical potential, but it will still allow it to pass if that difference is too important ?

The idea is good Alain. But I'm afraid this is about unknown currents happening (meaning the undoubtedly higher ones) and now I don't think that there will be a "balance" resistor value to cover for all.
Notice that the connection did not originate from "protection" as such, but that we mangle the PC side. And now I suddenly regard it "protection".

(this is all about the USB goes over PE stuff - which those new to the subject won't get from this small topic here)

Peter

Yes I understand... I am not myself at ease with this, as if I am walking in a minefield...

Alain