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New test shows loose RTX 4090 power connectors cause overheating and melting

    Nvidia's RTX 4090.
    Enlarge / Nvidia’s RTX 4090.

    Sam Machkovech

    A few weeks ago, some early adopters of Nvidia’s new flagship RTX 4090 GPU started reporting that the cards’ power connectors overheated and their plastic casings melted, sometimes causing damage to the insanely fast and expensive GPUs.

    On the part of Nvidia, the company is still investigating the failures. “We continue to investigate the reports, but we have no further details to share yet,” said an Nvidia representative in conversation with KitGuru earlier this week. But the YouTubers on the Gamers Nexus channel have done their own in-depth research, and in short, they believe the problems are mostly caused by misplaced power connectors. “Dirt from foreign objects” in the connector can also cause problems, but Gamers Nexus believes this type of damage is much rarer.

    The failure that Gamers Nexus was able to replicate in its labs involved plugging the 12VHPWR power connector into an RTX 4090 without fully inserting it and then bending the cable to one side, making the connection even worse. After just a few minutes of testing, the high current resistance of the loose connection generated heat in excess of 250° Celsius, causing smoke and visible bubbles as the connector melted into its socket.

    A still from the Gamers Nexus test video.  A visibly loose connection combined with a cable bent at a hard angle caused temperatures to rise rapidly and eventually smoke and melt.
    Enlarge / A still from the Gamers Nexus test video. A visibly loose connection combined with a cable bent at a hard angle caused temperatures to rise rapidly and eventually smoke and melt.

    Gamers Nexus describes the problem as “a combination of user error and design oversight”. Namely the cables to be melt because they are not fully inserted. But the lack of a tactile “click” sound or a more robust retention mechanism makes these types of errors more likely with the 12VHPWR connector than with the older 6- and 8-pin PCIe power connectors. The size of the 4090 and 4080 cards also exacerbates the problems. The cards can fit snugly even in relatively roomy ATX PC cases – you may need to bend the cable in some way to get your case closed again, and this kind of bending can cause the loose connection that contributed to overheating and melting in the Gamers Nexus tests.

    In particular, the malfunctions can have an influence each cable or adapter using the 12VHPWR connector – this applies to both types of adapters that Nvidia and its partners have used for 4090s thus far, as well as “native” 12VHPWR cables that run directly to a power supply with no adapter in between. Previous analysis suggested that some manufacturer’s adapters may be more prone to interference than others, but Gamers Nexus didn’t think it made a difference. This presumably also means that 12VHPWR adapters that come with the RTX 4080 cards can have the same issues.

    For now, it’s best to be absolutely sure that your power connector is firmly in place – if it is, you should be able to pull it pretty hard without actually pulling it out (we got to test this firsthand). You should also be careful to avoid any hard bending of the power cable in any direction. We’ll keep an eye out for an official statement from Nvidia to see if it has any further recommendations or plans for any kind of recall or replacement of the affected cards.