The first reported case of an AMD RX 9070 XT melting a 16-pin power connector is here, but I'm not sure we should prepare ourselves for another 'meltgate' just yet
Ah, I almost feel nostalgic. Remember 'meltgate', in which 16-pin 12VHPWR connectors were regularly in the headlines for, well, melting under heavy usage or incorrect installation? The problem appeared to be limited to certain Nvidia cards like the RTX 4090, as they were the ones making use of the connector standard at the time, before the spec was eventually updated to 12V-2x6.
Now the first case of a 16-pin 12V-2x6 connector melting in an AMD card has been reported (via Wccftech), and if you did a double-take like me, you're in good company.
UPDATE: Yea it melted.... 12VHighFailiureRate Strikes again. from r/radeon
The RX 9070 XT in question is an ASRock Taichi OC model, which makes use of the 12V-2x6 16-pin connector, unlike most RX 9070 XTs that use multiple 8-pin models. According to reddit user Savings_Opportunity3, they first noticed darkened pins on their card's cable connector roughly a month ago, before confirming it's now melted to a considerable degree.
Before we all grab our pitchforks and go marching into the streets, however, it's worth noting that said redditor was using a 3x8 pin adapter cable that they've confirmed is on its fourth mating cycle.
While I'd say this was well within tolerances for a cable connector's expected lifespan, each cycle introduces the possibility of an incorrectly seated connection, which is believed to have been one of the primary causes for a number of previous connector-melting reports. So much so, in fact, that MSI went to the trouble of colouring the plastic surrounding the pins a luminous yellow, so users could easily tell if they hadn't pushed it the whole way in.
Still, if the adapter cable in question was a cheap, third-party unit, it's possible that some shoddy wiring could lead to differing pin impedances, where one pin ends up drawing more current than its rating can handle. Never mind the connector plastic itself, where loose tolerances could cause it to seat incorrectly, even if it appeared to be fully inserted.
The redditor in question also appears to have used a 700 W PSU, while AMD recommends at least a 750 W unit for the RX 9070 XT. This has led some commenters to speculate that the power supply could potentially be to blame, although personally, I don't think a slightly under-specced unit is likely to provide too much current to a card. Generally, when too much draw is demanded from a power supply, it will instead cut off power entirely, causing the machine to reboot.
Still, don't skimp out on your PSUs, people. Cheap units have been known to behave in all sorts of strange ways, so if you're considering upgrading your PC with a new graphics card, you should seriously consider upgrading your power supply to something from a respected brand. Don't mix PSU cables between models, either—that's a big no-no, and if you do, I'll be very disappointed in you.
All that being said, I'm inclined to lean towards user error on this one. It seems to have been behind most of the reported cases of melted power connectors so far, which means this story should likely serve as yet another warning for DIY builders to check, double-check, and then check their power cable connections again. Better to be safe than melty, right?