Tom's Hardware takes a look at NVIDIA's new RTX 50 series GPUs, and the increasing number of reports saying these may suffer the same 12VHPWR connector issue that caused melting problems on RTX 4090 cards. A new video from der8auer uses thermal imagery to show overheating cables, and this video from Actually Hardcore Overclocking breaks down its findings further, saying the new cards make the connector "even worse" (thanks Diabolik). The article on Tom's summarizes some test results suggesting the overheating is due to uneven power distribution:

Just 45 seconds into the test, two of the six 12V wires shot up to nearly 60 degrees Celsius. On the PSU end, Roman witnessed a hotspot of almost 130 degrees Celsius, spiking to over 150 degrees Celsius after just four minutes. With the help of a current clamp, one 12V wire was carrying over 22 Amperes of current, equivalent to 264W of power. For context, the 12VHPWR and 12V-2x6 standard allows for a maximum of 9.5 Amperes through a single pin. The reported current readings for the remaining five wires were: 2A (24W), 5A (60W), 11A (132W), 8A (96W), and 3A (36W) with a moderate margin of error as it's hard to get precise measurements across all wires concurrently.

In short, uneven current distribution leads to dangerously high temperatures which can potentially burn or melt the cable and damage connected components. In isolation, this incident could've been swept under the rug as a one-off, however, Roman's near one-to-one recreation of the problem suggests there's something else at play here.