Thank you for your bug report. What's the output of the "xrandr" command when the external monitor is connected/configured?
** Changed in: unity-control-center (Ubuntu) Importance: Undecided => Low ** Changed in: unity-control-center (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to unity-control-center in Ubuntu. https://bugs.launchpad.net/bugs/1577701 Title: Cannot use external monitor Status in unity-control-center package in Ubuntu: Incomplete Bug description: I am running an HP 455 G2 Laptop, AMD A series A8-7100 1.8 GHz, 4GB RAM, 500GB HDD, 15.6" Display, DVDRW, AMD Radeon R5, Webcam, Bluetooth with Ubuntu 16.04; upgraded from 15.10. Under 15.10 I connected and used an acer vga monitor. After the upgrade to 16.10 the second monitor has no display. Steps to reproduce: Disconnect monitor; restart computer. Enter "Screen Display". confirm only one (internal) monitor is shown. Connect monitor. Click "detect displays". Monitor is detected and shown in grey (screenshot 1) Select acer monitor; click "on" at slider. (screenshot 2) Click "Apply". No display on acer monitor. Click "Keep this configuration". Still no display on acer monitor, however mouse is not held at edge of laptop screen - ie the computer thinks the external display is in use. Also windows can be pushed entirely into the extended desktop (but are then, obviously, not visible). The little indicator light on the monitor switch remains in the amber "no signal" condition. Now click "power > shut down > shut down" As computer shuts down the purple screen with line of dots lighting up appears on BOTH the built in screen AND the external screen. On restart, the computer still thinks the external screen exists and is active, but there is no display. ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: unity-control-center 15.04.0+16.04.20160413-0ubuntu1 ProcVersionSignature: Ubuntu 4.4.0-21.37-generic 4.4.6 Uname: Linux 4.4.0-21-generic x86_64 ApportVersion: 2.20.1-0ubuntu2 Architecture: amd64 CurrentDesktop: Unity Date: Tue May 3 10:19:01 2016 ExecutablePath: /usr/bin/unity-control-center InstallationDate: Installed on 2016-02-26 (66 days ago) InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021) ProcEnviron: PATH=(custom, no user) SHELL=/bin/bash LANG=en_GB.UTF-8 LANGUAGE=en_GB:en XDG_RUNTIME_DIR=<set> SourcePackage: unity-control-center UpgradeStatus: Upgraded to xenial on 2016-04-22 (10 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/unity-control-center/+bug/1577701/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp