Gabriel Zhi Chen, thank you for reporting this and helping make Ubuntu better. Could you please execute the following command, as it will automatically gather debugging information, in a terminal: apport-collect 1434372
Please ensure you have xdiagnose installed, and that you click the Yes button for attaching additional debugging information. ** Package changed: linux-lts-utopic (Ubuntu) => xorg (Ubuntu) ** Changed in: xorg (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1434372 Title: [Lenovo E555] Screen of laptop will become black and never lighting after un-plug VGA cable Status in HWE Next Project: New Status in xorg package in Ubuntu: Incomplete Bug description: CID: 201408-15472 Lenovo E555 (A+A) with 14.04.2 (utopic) Steps: 1. Install 14.04.2 on E555 2. Install fglrx 3. Reboot system and log in 4. Plug in a VGA cable and switch 4 modes by display key. (external, internal, extand and mirror) 5. Un-plug VGA cable, observe screen result. Expected results: Labtop screen display normally. Actual result: Labtop screen became black and never lighting. Only press power button off/on machine, that could make screen light again. ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: linux-image-3.16.0-30-generic 3.16.0-30.40~14.04.1 [modified: boot/vmlinuz-3.16.0-30-generic] ProcVersionSignature: Ubuntu 3.16.0-30.40~14.04.1-generic 3.16.7-ckt3 Uname: Linux 3.16.0-30-generic x86_64 NonfreeKernelModules: fglrx ApportVersion: 2.14.1-0ubuntu3.7 Architecture: amd64 CurrentDesktop: Unity Date: Thu Mar 19 23:58:26 2015 InstallationDate: Installed on 2015-03-18 (1 days ago) InstallationMedia: Ubuntu 14.04.2 LTS "Trusty Tahr" - Release amd64 (20150218.1) SourcePackage: linux-lts-utopic UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/hwe-next/+bug/1434372/+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