Steve from Harbor Unboxed experienced dangerous overheating and melting of the 12-volt high power connector cable on his Nvidia RTX 5090 graphics card due to a PSU connector failure causing uneven current distribution. Using the Thermal Grizzly WireView Pro, he identified the issue early, highlighting the importance of monitoring power connectors on high-end GPUs to prevent hardware damage and advising users to replace worn cables promptly.
In this unexpected video, Steve from Harbor Unboxed shares a concerning experience with his Nvidia RTX 5090 graphics card’s 12-volt high power connector, which began overheating to dangerous levels during routine testing. While running a looped demo in Doom Eternal, he noticed the connector cable became excessively hot—hot enough to burn his hand. Using a Thermal Grizzly WireView Pro, a device that monitors electrical current and temperature in cables, Steve identified a severe load imbalance where only two of the six power wires were carrying current, causing extreme heat buildup.
Upon closer inspection, Steve discovered visible melting and bubbling on the cable near the graphics card end, indicating insulation failure due to the high current load. Despite the cable appearing intact at first glance, the WireView Pro revealed that some pins were no longer conducting electricity, which explained the overheating. Testing further showed that the problem was not at the cable’s GPU end but rather at the power supply unit (PSU) connection, which had melted and fused the cable pins inside the PSU connector, making cable removal difficult.
Steve highlighted that this issue is not isolated to his setup; it is a known problem affecting various RTX 5090 cards and different power supplies, including high-end models like his be quiet! Dark Power 13 PSU. The PSU’s internal connector failure caused current to be forced through fewer wires, resulting in dangerous heat and potential catastrophic damage to both the cable and components. Fortunately, the graphics card itself remained undamaged, but the PSU and cable were severely compromised and required replacement.
The video underscores the importance of monitoring power connectors on high-end graphics cards, especially those using the 12-volt high power connector. Steve praised the Thermal Grizzly WireView Pro for its ability to detect these issues early, potentially preventing hardware damage. He advised users to replace cables showing any signs of wear or overheating and to be vigilant for symptoms such as uneven current distribution or excessive heat.
Steve concluded by acknowledging the inconvenience and risk posed by this problem, especially given the high cost and limited availability of RTX 5090 cards. While this video was unplanned and more informal than usual, it serves as a cautionary tale for enthusiasts and professionals alike. He plans to replace the faulty PSU and cable to continue using his system safely, hoping others take note of the risks associated with these powerful components.