Custom CableMod 16-Pin Power Adapter Melts on RTX 4090

12VHPWR
(Image credit: Humble-Brilliant-654/Reddit)

After it transpired that Nvidia-supplied 16-pin 12VHPWR adapters could melt if improperly mated with the GPU, several manufacturers introduced their custom 12VHPWR adapters designed to be more reliable. Apparently, at least one of such adapters failed and melted when used with a GeForce RTX 4090 graphics card, according to a Reddit post. CableMod, the manufacturer of the device, promised to replace the product. 

A redditor named Humble-Brilliant-654 posted a picture of his 12VHPWR cable adapter that was clearly melted. He said that he inserted the adapter correctly until he heard the click and the device functioned without problems for two months. Some of the other Redditors said that the cable was not inserted properly, which is why it failed. Indeed, some of the marks on the cable's connector seem to indicate that it was plugged in properly, but it could have wiggled loose after installation. 

Meanwhile, CableMod said it would replace the unit anyway. "Very sorry about that - please reach out to our support and we will make it right with you," a statement by CableMod reads. "Our products come with service and we help every customer out." 

After investigating about 50 cases of overheated and melted 16-pin 12VHPWR cable adapters, Nvidia said that a common issue was that the connectors were not fully plugged into the graphics card. The company suggested plugging the dongles before installing the graphics card into the motherboard. 

Plugging in power connectors properly is extremely important since virtually all cables can overheat when connected poorly. Meanwhile, it is vital to properly plug in the connector on Nvidia's flagship $1,599 product since the graphics card can draw up to 450W of power from the PSU, and transferring such a vast amount of power requires high-quality cables and solid connectivity.

For now, we'll have to wait and see if CableMods shares any information about the failed connector. Thankfully there haven't been many reports of failed connectors with Nvidia's connectors lately, a trend we'd like to see continue. 

(Image credit: Nvidia)
Anton Shilov
Freelance News Writer

Anton Shilov is a Freelance News Writer at Tom’s Hardware US. Over the past couple of decades, he has covered everything from CPUs and GPUs to supercomputers and from modern process technologies and latest fab tools to high-tech industry trends.

  • TechieTwo
    While fully connecting the plug is quite important no one has confirmed this is the real or only issue with melting power connectors. on the RTX 4090 and other models.
    Reply
  • 2Be_or_Not2Be
    The original design specs should have required a locking connector to ensure it's secured & seated fully. Still basically Nvidia's fault here, although they'll never own up to it.
    Reply
  • InvalidError
    No amount of aftermarket wiring will save people from plugging their connectors half-way in.

    TechieTwo said:
    While fully connecting the plug is quite important no one has confirmed this is the real or only issue with melting power connectors. on the RTX 4090 and other models.
    Since you can chop half the connector off and still get no meltdown when the remaining half is fully connected, it seems exceedingly unlikely that there is any other significant issue.
    Reply
  • TJ Hooker
    2Be_or_Not2Be said:
    The original design specs should have required a locking connector to ensure it's secured & seated fully. Still basically Nvidia's fault here, although they'll never own up to it.
    The 12VHPWR connector does have a locking mechanism.
    Reply
  • rz350lc
    If the locking mechanisms were on the ends it would have to be inserted properly to lock.
    Reply
  • InvalidError
    TJ Hooker said:
    The 12VHPWR connector does have a locking mechanism.
    A retention tab isn't much of a locking mechanism. He likely meant something with a more positive locking action such as cam-lock levers similar to some DIMM slots where the levers cannot engage the retention notches until the connector is all the way in to make them line up.
    Reply
  • Viking2121
    Yeah, them connectors need an overhaul, yeah I know its user error not plugging them in fully, but there needs to be a way to make the user plug them in fully for it to even work to avoid this issue to begin with.
    Reply
  • umeng2002_2
    The issue with the new plug is that locking mechanism is much smaller, so it's harder to see and/ or hear it snap into place. With black plastic, in a dark case, close to a heatsink, it's very hard to even get a good view of the two mating surfaces to verify that they are all the way in.
    Reply
  • Elrabin
    Viking2121 said:
    Yeah, them connectors need an overhaul, yeah I know its user error not plugging them in fully, but there needs to be a way to make the user plug them in fully for it to even work to avoid this issue to begin with.


    PCIe SIG has already changed the adapter / cable spec so that if it's not 100% mated, it will throw an error and not power the card.

    PCI-SIG is revising the connector
    "The currently planned changes will only affect the four Sense Pins, but they are quite a real solution. Due to the shortening of the contacts, the sense pins only become contactable when the plug has been fully inserted"
    "this means that the graphics card will no longer start without the first two sense pins being assigned or recognized. Only PCI SIG itself knows why this was not planned from the outset. If, in a second step, the shape of the connector housings could be corrected by specifying beveled or chamfered edges, a large part of the problems on the customer side would automatically disappear"
    Link to the reddit megathread
    Reply
  • Amdlova
    Secure the connector with gaming zip ties lol.
    The old 8 pin connector is alot better
    Reply