Question DisplayPort bridge to Type-C video-out gives fixed white led on the motherboard ?

[Oiram07]

Hello everyone!

Motherboard: Asus ProArt Z790

GPU: Asus ProArt RTX 4070 Ti

I have just built a new PC and having one issue:
I am sending the video signal to my monitor (BenQ PD3220U) via the Type C out on the motherboard, using the RTX 4070 Ti.
The GPU DP out is connected to the DP-In 1 on the MB using the provided cable, the monitor is connected using the Type C 1 out as per manual.
Powering on I can't access or even see the BIOS booting screen, I directly enter into Windows (11) log-in. Once logged in everything works fine.
But on the motherboard the white error led is permanently on.

If I use a DP cable out directly from the GPU to the monitor everything's normal: I can see boot screen, access BIOS and the white led is off.

Latest BIOS on the MB and everything is updated.

Any clue what's happening?
Thanks!!!

 

[helpstar]

try HDMI

 

[Oiram07]

try HDMI

HDMI and Displayport both work. I'd like to fix the Type C issue but the fastest workaround is just to stick to DP.
Thanks for your reply!

 

[Oiram07]

Uh...restarting the PC fixes the thing. It looks like it's a monitor issue rather than a MB's.
It's as if the monitor can't show anything fast enough at first start.
Monitor is a BenQ PD3220U

 

[helpstar]

try setting the monitor´s source directly to DP/USB instead of auto

 

[Oiram07]

monitor's set to thundebolt now and works (white led is off).
The Auto Switch option in the monitor's OS Menu is grayed out.

 

[Oiram07]

After quite some reasearch I think the most likely to be at fault is the power supply to the RTX, either the adapter 12VHPWR 2x8pin or the PSU PCIe cables. Maybe 3X8pin would be a better solution.
I think the red led on the RTX (normal if you listen to Nvidia) at shut down and the white led at power up are linked by the same problem.

 

[Oiram07]

Update: the culprit is XMP, if I keep it inactive the Ram stays at 4800 but Thunderbolt works always.
No clue why.
My kit is Kingston FURY Beast DDR5 64GB (2x32GB) 5600MT/s DDR5 CL40 DIMM Memoria Gaming per Computer Fissi Kit da 2 - KF556C40BBK2-64.