I bought the U-3900 in order to be able to run all the peripheral devices (screens,keyboard, mouse etc) for which ever device (desktop or laptop or ultabook) got plugged into the USB port. Unfortunately I have two old monitors that take DVI or VGA input only, so I bought an adaptor to convert HDMI to VGA. Using the DVI port on the U-3900 works fine on both monitors but when using the HDMI/VGA connection the screen is blank. The computer recognises the display as it is visible on the control panel–>appearance–>display–> ‘screen resolution’ set-up - in actual fact it recognises 3 screens though I only have 2 - but there is no picture. I can’t see anything in the HDMI/VGA connector specification that suggests its passive but could that be the issue? Do I need a better connector or a new monitor to get this to work?
Thanks for contacting us. I’d be happy to help with your docking station!
Based on your description of the dock’s DVI output working properly I would suspect the HDMI to VGA adapter you are using is the culprit. The quality of HDMI to VGA adapters varies widely, so we started offering our own solution –> http://plugable.com/products/hdmi-vga. Are you using our Plugable brand HDMI-VGA cable or a different brand?
Pending that information, do both monitors offer both DVI and VGA inputs? If that is the case you could also try using a HDMI->DVI cable like this one –> amazon.com/dp/B00K7HECTQ to connect the second display. That isn’t our product and we couldn’t provide support for it, but several of our customers have reported good results.
Let us know if that information helps when you have a moment and we’ll go from there.