Kubuntu Intrepid Ibex (8.10) on my laptop makes the screen flash on and off repeated every 10 seconds or so. The video output is actually turning on and off. It was driving me crazy. Here’s how to fix it.
My laptop has an Intel 945GM but this problem seems to affect other cards such as the GMA915 and some ATI as well. It has also manifested itself as flicker, rather than the periodic blanking that I’m experiencing.
According to bug 278471, this problem is associated with the monitor detection function in KDE4. So, to stop the flickering, flashing and blanking, simply turn off the detection service as follows.
- Click on the K menu
- Go to the Applications tab
- Click on the System menu followed by System Settings
- In the System Settings window, click on the Advanced tab
- Click on the Service Manager
- In the Startup Services list, select the service named, “Detecting RANDR (monitor) changes” so that it’s highlighted
- Click the Stop button to stop the service, then click the checkbox to clear it (so it doesn’t start up anymore)
- Click the Apply button
Voila! No more flashing. What a relief. After this bug is fixed, you can turn the service back on so that Kubuntu can detect monitors again.