I have a very similar behaviour on my i7 PC with two Benq monitors: 23" vga and 24" dvi. Dvi one can blink several times in a row or not to blink for some long time. Haven't found any consistent pattern about it. I am running Ubuntu Gnome 15.10 that I have upgraded to 16.04 recently. Problem was from very beginning and continues after upgrade.
** Attachment added: "diag.zip" https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/349943/+attachment/4664401/+files/diag.zip -- 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