System does not boot up without connected to external monitor via HDMI

[Tomáš Kalász]

Hello guys,

yesterday I just updated Ubuntu Gnome from 15.10 to 16.04. I have an external monitor connected to my Asus G55VW notebook via HDMI. After the update there weren't any problems until today, when I brought out my notebook from my room (unplugged HDMI). When I turned it on and after selecting "Ubuntu" on the Grub screen, the notebooks screen starts to flicker and nothing happens.

After a few trying I brought it back to my room, connected to my external monitor and the system booted up. I turned off the second screen in the Display menu, but it didn't help. I changed the nvidia driver back to version 340 from 36x, but it didn't help neither.

So at this moment I can only use my notebook with an external monitor. Interesting is, that when the screen flickers and I connect it to the monitor, the system boots up automatically, without restarting.

Notebook config:
CPU: Intel Core i7-3610QM
GPU: nvidia 960M GTX,
RAM: 8GB
SSD: SanDisk U100 128GB

[Tomáš Kalász (tomi-kalasz)]

Sorry, the GPU is: GTX 660M

[Tomáš Kalász (tomi-kalasz)]

I'm adding some log files here.

[ImperfectLink (imperfectlink)]

Same notebook and same problem here. It happens with both Ubuntu Gnome and Ubuntu Unity. Haven't tested flavours.
 I thought it might be the GPU driver but all of them do the same thing.
I also tested booting into kernel 4.2 but also doesn't work.
 I thought it might then be Gnome 3.18 but Fedora 23 works.

This happened in both the beta and the release of Ubuntu.

[Tomáš Kalász (tomi-kalasz)]

Well, I think it's a global Ubuntu problem, a guy with an AMD APU has similar problem as this: http://askubuntu.com/questions/763084/system-does-not-boot-up-without-connected-to-external-monitor-via-hdmi?noredirect=1#comment1140918_763084

[ImperfectLink (imperfectlink)]

I've installed 16.04 on two other machines (one Gnome, one unity) without this problem.

[Patrick Garraud (pgarraud)]

Also have the same problem on Ubuntu 22.04 with a Dell Precision 5530 2in 1 laptop.