[INFO] - Flickering monitor not connected to KVM

[Mr Davo]

Hi Everyone,

I am running a Windows 7 computer, with a 3 monitor setup. The centre monitor that I use is a Shimian (2560 x 1440) and I have satellite monitors Dell (1920 x 1080) on the left and right sides.

When I came into work yesterday I was shocked to see the following (please watch this YouTube video) of my monitors...

Strange Monitor Behaviour

My first instinct was that perhaps something was wrong with the Shimian monitor, or the graphics card. However after performing some diagnosis I came to the conclusion that a KVM that I had plugged into the right satellite monitor was the source of my grief!

I find this particularly interesting because the Shimian is connected by HDMI, and had nothing to do with the KVM! My left satellite monitor connects by mini DisplayPort, my centre monitor connects by HDMI, and my right monitor did connect by KVM switch.

I can only conclude that the KVM was causing the graphics card to overload, and as a result affecting the output on alternative video connectors (i.e.: HDMI, mini DisplayPort).

Here are some shots of my old KVM for interest sake -

I have written this post in the hope of helping others who may be experiencing display issues related to a KVM, and to let people know that a monitor doesn't have to be plugged into a KVM to be affected by the presence of a KVM on a multi-monitor system.

Please don't take this as a warning off KVM switches, or a slant on any particular KVM brand - I did use the pictured KVM happily for several years before this happened.

Kind Regards,

Davo

 

[SandeepP]

Hi Davo,

Thanks for this insightful information. I am sure it would help other users as well facing the same issue. Quite a strange diagnosis that KVM for different monitor is causing flickering on monitor connected with different port.

Thats why they say troubleshooting is about thinking outside the box.