Hello I have troubles with my laptop detecting the external monitor. I am using Lenovo thinkpad p15 G1.

The external monitor is connted through HDMI. Until an update (sudo apt-get update) it was detecting it normally, and in windows (laptop using dual boot) it used the second screen successfully. I already solved it once by reinstalling ubuntu but the issue came up again. Find some diagnostics (and please let me know of any additional ideas):

Nvidia X server :

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sudo lshw -C display:

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xrandr output

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xrandr output from when the system was working fine:

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drivers used :

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All input will be appreciated.

With tensroflow gpu and python3 it cannot detect the nvidia card:

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lspci | egrep -i "vga|display|3d"
00:02.0 VGA compatible controller: Intel Corporation UHD Graphics (rev 05)
01:00.0 VGA compatible controller: NVIDIA Corporation TU106GLM [Quadro RTX 3000 Mobile / Max-Q] (rev a1)

EDIT (1):

I tried switching between drivers version 450 and 460 and restarted the system but not luck.


Going to discrete mode from bios prevents ubuntu having any display after GRUB. I resetted the option to hybrid. So I think it uses only the intel integrated gpu mode.

Edit(3) FINALLY SOME PROGRES: After putting the the open source drivers the monitor is detected, but the nvidia card is still not detected by python tf gpu:

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1 Answer 1


The problem was having Secure Boot enabled in UEFI and unsigned drivers (Nvidia's).

Either disable Secure Boot in UEFI (easy) or use mokutil to enable "trust" for the Nvidia's driver modules (not easy).

Other thing that worked:

After experimenting with the available drivers I report that my second monitor was detected successfully using r'the xorg open drivers, though I am not sure if this happens with gpu drivers which I think are still not detectable by the system. I opened a separate issue since the original question regarding the monitor is solved. (new question is here: nvidia drivers not working on ubuntu 20.04 with Nvidia quantum rtx 4000)

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