Fully seat every connector
Make sure the 12V-2x6 connector is fully inserted, latched, and has no visible gap.
Check all connections, GPU, adapter and PSU.
16-pin connectors: risk and solutions
What are 12VHPWR and 12V-2x6 connectors?
12VHPWR and 12V-2x6 are the recent compact 16-pin power connectors for modern graphics cards, the one that has been notorious for melting.
The melting problem
The fundamental issue is a design flaw in how power is distributed and monitored through the 16-pin connector on the newer GPUs that use it.
RTX 30-series cards used to balance the current between the connectors and the wires. This is no longer the case from the Nvidia RTX 40-series and AMD cards using this connector.
This leaves the door open to a current imbalance within the 16-pin connector, which can cause heating and possibly melting. When the connector melts, it often creates a dangerous short circuit and hardware damages.
Cards down to 300W have been affected by this issue; it is not limited to high-power cards.
Important
This does not require user error. The problem can occur at any time, because the underlying design does not actively prevent this type of current imbalance.
INSTALLATION ADVICES
Limit the risk
Avoid sharp bends and mechanical pressure
Route the cable gently, and avoid bending, twisting, or applying side pressure directly behind the GPU connector. Make sure the case side panel is not pushing against it.
Do not use damaged cables/connectors
Stop using any connector that shows melting, discoloration, deformation, damaged insulation, or any other sign of overheating.
This is true both for the GPU side and the PSU side
Use separate PSU cables
If you are using a 8-pin to 16-pin adapter connect each 8-pin adapter plug to a separate PCIe cable or PSU output, rather than two plugs from the same daisy-chained cable. This helps avoid concentrating the current in a single cable.
ACTIVE PROTECTION
Thermal Grizzly WireView: the only universal option
The Thermal Grizzly WireView is different from a passive cable or adapter: it actively monitors the 12V-2x6 connection while the GPU is running, including per-pin current, power, and connector temperature.
This makes it the only broadly universal aftermarket solution that actively detects the current imbalance. If abnormal values are detected, it can issue warnings and is capable of automatically stop the system before the connector is damaged.
Our advice
It is worth spending a little extra on this protection to prevent far more expensive damage, especially if you run a demanding graphics card.