RX460 not detected on boot without a monitor plugged in AND turned on?

[rhaenys]

I have reasons to believe my new GPU is bad, and I'd like some confirmation that the following behaviour is abnormal:

The GPU won't be detected by the computer unless it goes through POST with a monitor not only connected to it, but turned on. Trying to boot without any monitor, or with a monitor plugged in but turned off (through the button, not "not powered" at all) will result in the GPU not "starting up". The system will act as if there was no dedicated GPU at all.

Has anyone ever seen such behaviour in "healthy" GPUs?

I should add that:

■ The BIOS display settings are correct.
■ The display cable is certainly connected to the GPU, not the motherboard.
■ Tried multiple monitors and different cables (HDMI, DVI).
■ The GPU is receiving enough power. No starving symptoms once it's detected, the PSU is also new, providing the correct voltages, from a reliable enough model and more than the build needs. The GPU also uses no external power connector.
■ Also updated BIOS among other things, to no avail. The mobo itself was RMA'd and carefully tested by the manufacturer.
■ The GPU behaves consistently in this aspect, it always works if a turned on monitor is connected during cold boots, otherwise it's never detected.

The GPU is a Powercolor RX 460, mobo is a Gigabyte H170N-Wifi and PSU a Corsair CX 430.

Thanks in advance.

 

[hang-the-9]

You did a motherboard RMA, did you contact the video card vendor and check with them what may be happening?

 

[rhaenys]

You did a motherboard RMA, did you contact the video card vendor and check with them what may be happening?

Not yet, but I'll RMA that card (details below). Powercolor doesn't offer direct RMA in my country, I need to send it back to the seller. I've been less than eager to do this because they're one of the biggest companies here and fully know it, sometimes throwing their weight around to deceive people during legit RMA requests.

RMA reasons:
Perhaps not starting up without a monitor is how this card was designed, but failing to be detected (with a monitor and everything) in 1 out of 4 restarts surely isn't. This card also randomly crashes when I'm already using Windows/Linux and the only way to stabilize it is forcing it to use PCIe gen1 speed, so it won't change speeds and trigger the crash.

Once my RMA is completed I'll post here whether this "no monitor = no GPU" thing is expected with this model or it's yet another symptom of a bad card.