Oh, thanks for all of you reported this issue. I'm using Ubuntu20.04.2 now, and encountered the exactly same issue as you met about 12 years ago on Ubuntu9.04. It seems this is a very old bug in Ubuntu or linux bug on its HDMI driver. And because not so many people using external HDMI monitor, so this issue couldn't be paid attention to for linux/Ubuntu engineering team.
-- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/349943 Title: Screen blinks randomly on external monitor Status in xorg package in Ubuntu: Won't Fix Bug description: Hardware: Asus F8Va laptop (Core 2 Duo P8600, ATI HD3650, 1440x900) OS: Ubuntu 9.04 beta x64 (Wubi installation inside Windows Vista Home Premium x64 SP1) External monitor (Samsung SyncMaster 2493HM, 1920x1200), connected via HDMI, blinks several times a minute, randomly. When there is no user activity, it doesn't seem to blink however. By "blinking" I mean, the monitor goes off and then on, like it usually does when it changes resolution, only resolution doesn't change. Also, when I move windows around, thin horizontal stripes flash in fraction of second from time to time (only on external monitor). Screen configuration: Samsung 24": On Resolution: 1920x1200 Refresh rate: 60 Hz Rotation: Normal Laptop 14": On Resolution: 1440x900 Refresh rate: 67 Hz Rotation: Normal Mirror screens: unchecked Relative position of screens (physical and in Display Preferences) laptop screen below the external screen, centred. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/349943/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
