CPU and GPU power

bnzSup · January 16, 2021

So... the other day I was helping my Father in law build a pc for my girlfriends brother and we built everything, but when it was time to power it on everthing lighted up, the fans, the CPU cooler, except the GPU. So we removed the GPU and tried placing it again, didn't work. After that, we forgot the 12V CPU power cable disconnected and turned on the pc, and for some reason the GPU turned on.

So what we know is:

When the CPU 12V cable is connected the GPU doesn't turn on, but if you disconnect it (the CPU 12V cable), the GPU turns on.

Here is the parts list:

https://de.pcpartpicker.com/list/2nZ9F8

The CPU and GPU are used.

WhitetailAni · January 16, 2021

2 minutes ago, bnzSup said:

So... the other day I was helping my Father in law build a pc for my girlfriends brother and we built everything, but when it was time to power it on everthing lighted up, the fans, the CPU cooler, except the GPU. So we removed the GPU and tried placing it again, didn't work. After that, we forgot the 12V CPU power cable disconnected and turned on the pc, and for some reason the GPU turned on.

So what we know is:

When the CPU 12V cable is connected the GPU doesn't turn on, but if you disconnect it (the CPU 12V cable), the GPU turns on.

Here is the parts list:

https://de.pcpartpicker.com/list/2nZ9F8

The CPU and GPU are used.

The power supply will activate if the 24-pin is plugged in and the power switch pins are shorted.

As the GPU is not CPU-dependent for activation, this will happen.

Do you get a POST with everything plugged in?
If not, you probably don't have a strong enough power supply.

bnzSup · January 17, 2021

On 1/16/2021 at 5:01 PM, ragnarok0273 said:

The power supply will activate if the 24-pin is plugged in and the power switch pins are shorted.

As the GPU is not CPU-dependent for activation, this will happen.

Do you get a POST with everything plugged in?
If not, you probably don't have a strong enough power supply.

No, we don't get any POST, the GPU doesn't turn on, so we can't enter BIOS either. The recommended power supply for this build is 400W and it is a 450W.