Trying to use a splitter cable to use 2 Monitors


I’m having problem using a spliter cabe with my Plugable switchbox.
The first monitor works fine, but the 2nd monitor just stays black.
Anyone know how to do this?
Thanks, Pat…


Hi Pat,

Thanks for posting and splitting out this splitter topic.

So from before, you mentioned you were using this product…

And a passive splitter like that won’t work, because it will create at least two problems: because it’s passive, it isn’t going to have the analog signal strength to drive two monitors for higher modes/refresh rates. And, worse, it will cause EDID information to be lost (or maybe only pulled from one of the monitors, from your symptoms) so Windows and DIsplayLink don’t know the capabilities of the monitors. The monitors would have had to have been exactly identical.

I’m not 100% what your goal is (let me know if I get it wrong), but if it’s just generally to add another independent monitor that you can use together to extend the Windows desktop with your existing monitors, what you’ll want is another USB graphics adapter which will plug into any of the available USB ports on your dock (or any other available USB port on the system).

Our $44.95 USB-VGA-165 is a good example of that kind of device (…), and it will work great with the dock (it shares the same drivers, won’t need to install any new).

If you really do want to have the same image on the external monitors 100% of the time and will be getting identical monitors, let us know, because then we could go to an active splitter (around $23) which will work.

Thanks for letting us know!


Hi Bernie,

Thanks for your help on this.
I guess I didn’t really explane the use of 2 monitors.
(Two - 20" Dell widescreen flat panels w/VGA cables)
My wife sometimes works from home …and using the little screen on her labtop doesn’t work real well for what she does.

At work she uses 2 mointors and wanted to achive this at home.

She runs 2 programs at once on 2 different screens.
The left screen would have a program with completed figures, and she needs to input those figures into the program on the right screen.

Hope this helps with the solution.

Thanks, Pat…


Hi Pat,

No problem - that’s great, because the answer is clear. You’ll definitely want and need another independent USB graphics adapter for that additional screen, so a product like the… is what you’re looking for. It can plug right into the dock (or any USB port), and it uses the same drivers you’re already running.

Thanks for giving that extra detail on what you were shooting for. Hope that helps!

Best wishes,


Hi Bernie,

I’m off to order the USB graphics adapter :slight_smile:

Thanks again for the help, I’ll let you know how it works once I get it setup.

Regards, Pat…


Hi Bernie,

Sorry for the delay …I have been really busy …but now the Boss (my wife :wink: is on me to get it working.

Ok …I have the new USB plugable adaper …and it’s plugged into the docking station.
I start the computer …and you can tell the monitors are getting power …but they just go to sleep mode.
So I have the labtop open and working …but both moitors have a black screen.

Please walk me through what I need to do now.

Thanks, Pat…


Hi Pat - I forgot to ask in the older exchanges: what operating system are you running? They have different UI, so that will let me know what steps to describe.



Hi Bernie,

Windows 7 …brand new HP laptop.



Hi Pat,

The first thing to check is if Windows has enabled use of the monitors. The quickest way to do that is to hit the “Windows-p” key combination, and in the menu bar that comes up, choose “Extend”


And you can get a lot more great detail in the DisplayLink User Manual here: http://displaylinkmanuals.s3.amazonaw…

Windows 7 specific information starts on page 12.

Let us know how that goes, and where in those steps things seem to be stuck.

Thanks again!