ASRock TempGuard Fails to Shut Down System After RTX 5090 Connector Melts

A high-end graphics card power connector melted on a user's system, and the safety cable designed to prevent such damage failed to trigger. This incident matters because it reveals a critical gap in the thermal protection mechanisms for the new 12V-2×6 power standard. Buyers relying on these cables for peace of mind should note that the automatic shutdown feature did not work as intended in this specific case.

Thermal protection cable did not trigger automatic shutdown during connector failure

The failure occurred on a build featuring an MSI GeForce RTX 5090 GAMING TRIO OC graphics card. The user connected this GPU to an ASRock PG1000-PSF power supply using a native 12V-2×6 cable equipped with ASRock's TempGuard technology. TempGuard is a cable designed to monitor connector temperatures and shut down the power supply when overheating is detected.

• Power Connector Type: 12V-2×6
• Protection Feature: TempGuard
• Protection Outcome: Failed to shut down system
• Affected Component: ASRock PG1000-PSF Power Supply
• Graphics Card Model: MSI GeForce RTX 5090 GAMING TRIO OC

Despite the connector melting, the TempGuard protection never triggered and the computer did not shut down automatically. The ASRock PG1000-PSF power supply reportedly continued operating after its native 12V-2×6 connector began melting. The user confirmed the cable was fully seated with no sharp bends prior to the failure, ruling out simple installation errors.

Expert Roman 'der8auer' Hartung analyzed the visible damage and believes one terminal carried much more current than the others. He pointed to Pin 1, which appears to have generated enough heat to damage both the cable and the PSU-side connector. Uneven current distribution likely caused Pin 1 to overheat and melt the connector.

The exact root cause of the melting is unconfirmed because the power supply has already been returned to Amazon. This prevents a physical inspection of the internal components to verify the current imbalance. This is the second RTX 5090 connector failure for the same user, previously involving a Founders Edition and Corsair PSU. We've been tracking RTX 5090 closely — see our earlier coverage on NVIDIA RTX 5090 Connector Melting Sparks.