I don’t know why, but it started working today again. To rule out a hardware failiure the BIOS option to use the HDMI as boot display is good. And this morning it just worked again?!?! I guess because I brought tho older brother Lenovo X1…

On Jun 25, 2019, at 22:08, Florian Wehner wrote:

Thanks so far! Last two mails collected here.

First guess: hardware failure?

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Does the display work at startup? Like does it POST and do you have a boot loader?

Not on the external screen. That was what I expected for the UEFI setting “Post on hdmi”.

That could lead to failed port?

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Do you have another device that you could use to check that the cable and monitor are not the issue?

Yes. Tested a TV, and a projector.

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What graphics card are you using and which driver?

Whatever is installed by default through pacstrap base

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Awhile ago I believe xf86 video intel was deprecated in favor of mode setting.

Thanks for pointing that out. I saw that here: https://wiki.archlinux.org/index.php/Intel_graphics#Installation

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Are you using UEFI?

Yes. Only. Systems Boot

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On Jun 25, 2019, at 20:03, Ralf Mardorf via arch-general wrote:

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On Tue, 25 Jun 2019 19:07:56 -0400, Florian Wehner wrote: I wasn’t able to get my HDMI output running on my Lenovo X1 Carbon 6th gen today. I run gnome on Wayland. It has been working fine for the last few days but completely dead today.

Did an update affect anything?

Might be. Mesa just got an minor update a few days ago. But I rebooted successfully at least once after updating.

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I'm using Driver "intel"

Where can I find this info?

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However, the "Multihead" Wiki, https://wiki.archlinux.org/index.php/Multihead, refers to "Related articles" for non-Intel.

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Symptom: The external display detects that an HDMI cable is connected (via ground?) but there is no signal.

Maybe no signal, but perhaps just +5 V, https://en.wikipedia.org/wiki/HDMI.

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Here’s what I tried: Switch from wayland to Xorg [snip] Looking at xrandr => Not connected

But xrandr shows one or more disconnected HDMI ports?

Yes. 2 disconnected HDMI ports shown. One cloned with a DP.

—Flo