KVM Switch help please

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Satch

1985 posts

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#97494 15-Feb-2012 17:19

Hi guys,

Hoping someone will be able to give me a helping hand with the setup of my new KVM switch.

The switch in question is a Rextron DAG12-BK. It handles DVI video. Connected to it I have the following:

A desktop PC with a DVI video card. The cable I have between the desktop PC and KVM switch is a DL-DVI-I cable
A laptop with a VGA output. The cable I have between the laptop and the KVM switch is a VGA cable with a DVI-A adaptor at the end which goes into the switch.
And finally, a DVI-D cable between the switch and the monitor (a Samsung 22 inch LCD)

Now I get video when the switch is connecting my PC to my Samsung monitor (and keyboard etc). But when I switch it to my laptop, I only get video on my laptop and not the Samsung monitor. I've set up dual displays etc, and the laptop can "see" my Samsung (it lists it in the settings).

I'm pretty sure it has something to do with the combination of cables I am using, but I don't really have a clue so if anyone can spot my mistake please let me know.

Cheers.

CYaBro

4582 posts

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#581967 15-Feb-2012 17:35

The problem is that the laptop is only putting out an analogue signal, which uses some different pins on a DVI plug.
It is still detecting the screen as some pins are common.
The DVI input on the screen is only for digital DVI signals.
If all you are needing the switch for is to share the screen then remove it and connect the DVI cable from the PC directly to the screen and the VGA cable from the laptop directly to the VGA on the screen.
Then use the input button on the screen itself to change from DVI/Digital to VGA/Analogue.

Edit: You could still keep the KVM if you are switching keyboard/mouse but it will mean pushing two buttons, one one the KVM and one on the monitor, to switch between PC & laptop.

Opinions are my own and not the views of my employer.

Satch

1985 posts

Uber Geek

#581968 15-Feb-2012 17:36

I think I've worked it out. It is the DVI-D cable from the KVM switch to my Samsung monitor which is causing the issue. It obviously only carries a digital signal, and not an analogue one too. Unfortunately my monitor only has a DVI-D input, and a separate VGA input.

I will be getting a new laptop within the next week or so which will also have a docking station or port replicator with it. The docking station has a DVI output, so I can only hope it is a DVI-D output so everything works ok then...

Satch

1985 posts

Uber Geek

#581970 15-Feb-2012 17:39

CYaBro: The problem is that the laptop is only putting out an analogue signal, which uses some different pins on a DVI plug.
It is still detecting the screen as some pins are common.
The DVI input on the screen is only for digital DVI signals.
If all you are needing the switch for is to share the screen then remove it and connect the DVI cable from the PC directly to the screen and the VGA cable from the laptop directly to the VGA on the screen.
Then use the input button on the screen itself to change from DVI/Digital to VGA/Analogue.

Thanks for your advice. I'm also wanting to share a keyboard and mouse, and use the Samsung as a second screen. Hopefully the docking station with my new laptop outputs a digital DVI signal as per my previous post.