[SOLVED] Please help! External monitor flashing red green blue and no display

[gabbar23]

External Monitor Lenovo Q24i-10 Monitor flashing red blue green while connecting to laptop.

 

[Ralston18]

Video cable fully and firmly connected on each end?

What video connectivity (VGA, DVI, HDMI, DP) are you using between laptop and monitor?

Try replacing the existing video cable with another known working cable.

Try another video connection option with a known working cable.