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Recently my laptop screen broke, so I removed the hinges from laptop and bought external monitor. Now my laptop boots into login screen [via VGA] cable into the monitor, but as soon as I login, the signal gets lost.

But here is the crazy part If I do Ctrl + Alt + F7 I login to tty4 and it shows up on monitor.

From internet, I tried running

sudo xrandr

but I get Can't open Display.

Here is the some of the command output I got from internet

lspci | grep VGA

00:02.0 VGA compatible controller : Intel Cor.... (rev 02)
01:00.0 VGA compatible controller : Advanced Micro Devices [AMD] ... 

How do I fix it so that after login screen it shows ubuntu. Since my boot screen is broken, I can't reinstall ubuntu.


Hello it seems that If I remove VGA cable and plug it back in it works..


share|improve this question
On the VT, run the xrandr command with the DISPLAY variable set: DISPLAY=:0 xrandr. Then post the output. Also please post the X log file from /var/log/Xorg.0.log. –  falconer Dec 30 '13 at 0:55

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