How to troubleshoot flickering of screen

    Hello...

    I have this odd behavior, that once in the blue moon, the screen flickers when i boot the system...

    It does not go away until i reboot...then it gone and good for a while until it eventually comes back at a boot...

    How could i troubleshoot such behavior?

    It sounds like a hardware problem. Loose or bad cable, motherboard or graphics card / chip problem. Even the power supply is suspect. Try giving it a good kick in the pants. ☺