The big TLDR is that the issue with the adapter is the connector's poor quality construction that leaves it fragile and easily susceptible to being damaged.

Combined with high amperage, the bending of cables and a user not be ultra careful with plugging in the cable, can result in hot spots that heat up enough to start melting the plastic.

The salt to the wound is that PSU manufacturers' 12VHPWR adapters are safer to use because of their more robust construction.

> A good example of a functioning connection are, for example, the two 12VHPWR cables of the new be quiet! Dark Power Pro 13, which I still show here as an example. Because there you don’t have to do the balancing act with the voltage bridges, but spend each pin its own 16AWG line. Sure, 12 thick wires in one cable is not that sexy now either, but it is at least an accurate and clean solution. I also snapped these cables right at the connector several times and did much of my testing for the GeForce RTX 4090 as well as the Intel Core i9-13900K in the lab with them on the redundant test system.

...

> The overall build quality of the included adapter for the GeForce RTX 4090, which is distributed by NVIDIA itself, is extremely poor and the internal construction should never have been approved like this. NVIDIA has to take its own supplier to task here, and replacing the adapters in circulation would actually be the least they could do. I will therefore summarize once again what has struck those involved (myself included) so far:

> - The problem is not the 12VHPWR connection as such, nor the repeated plugging or unplugging.

> - Standard compliant power supply cables from brand manufacturers are NOT affected by this so far.

> - The current trigger is NVIDIA’s own adapter to 4x 8-pin in the accessories, whose inferior quality can lead to failures and has already caused damage in single cases.

> - Splitting each of the four 14AWG leads onto each of the 6 pins in the 12VHPWR connector of the adapter by soldering them onto bridges that are much too thin is dangerous because the ends of the leads can break off at the solder joint (e.g., when kinked or bent several times).

> - Bending or kinking the wires directly at the connector of the adapter puts too much pressure on the solder joints and bridges, so that they can break off.

> - The inner bridge between the pins is too thin (resulting cross section) to compensate the current flow on two or three instead of four connected 12V lines.

> - NVIDIA has already been informed in advance and the data and pictures were also provided by be quiet! directly to the R&D department.

> Actually, I wanted to do something completely different today, but this correction was more important to me. Blanket panic and gloating are really bad advisors here when it comes to introducing new standards. That AMD has not (yet) joined the plug change was shown in my news about one of the upcoming board partners. But if you, like NVIDIA, take such a radical step, then at least the included accessories should work properly over after a little bending and ensure a safe, stable operation of the graphics cards.