RTX 3090 all voltages normal but not post

[hallmark1730]

Hello, Aorus 3090 xtreme model card does not post even though all voltages are correct.When I plug it in with another GPU, the motherboard stays on the GPU error light.That's why I can't test it from mats mods or check seems in windows.I checked the pex gate, there is 3.3 volt and 1.8 volt output.

The only problem I noticed is that the core heats up very quickly. When there is no heatsink, the voltages drop to 0V. But when the heatsink is installed, the voltages are constant.I measured the PCI lanes and there are no broken lines.I am open to all suggestions and recommendations.

[прямо]

Trace the PERST# signal. When it doesn't reach the GPU because a component has gone bad, some motherboards will not POST, while some others will continue to POST by simply assuming there's no GPU card inserted.

Without a heatsink VCORE drops to 0V is because the thermal protection kicks in. I hope when you noticed that it was within a 2 seconds window and you immediately turned off the power. You should never ever power up the GPU card without a heatsink especially power hungry modern GPU cards. You can damage the core.