Q: My laptop docking station is not HDMI, but the new monitors I bought to keep up here at the cabin are. I am looking to purchase converter adapters like these [links removed].
A: I am not sure what converter you need because the links you sent me are for different products.
DisplayPort, HDMI, and DVI are digital signals. VGA is the older analog video signal.
You can’t just use a passive cable with different connectors on each end to convert between analog and digital.
You need to use an active converter which requires power as well as the video signal.
There appear to be some simple cheap converters or cables on the market that are no more than connector type A hard wired to connector type B. If they work at all they won’t work well and could damage your equipment.
If you are converting from VGA to any of the digital video connections then the power has to be supplied by another cable, since the VGA video connector on a computer does not supply power. The converter may have an AC adapter you plug in to the wall, or it will have a USB cable that picks up power from a USB port on the computer.
If you are converting from DisplayPort or HDMI to VGA then it is possible the converter can get power from the DP or HDMI output on the computer.
Also note that because an active conversion is required, the cables/converters are generally not bidirectional. In other words, the same converter won’t work to convert VGA to HDMI and HDMI to VGA.
If your computer or docking station has a DVI-D output, you can convert this to HDMI with a passive adapter because because the basic digital video signals are essentially the same between DVI and HDMI. You can also passively convert HDMI to DVD-D with some limitations.
If your computer or docking station has a DVD-I output, you can convert to VGA with a simple passive adapter because DVI-I also includes the analog VGA analog signals.
When it comes to audio connections, VGA and DVI do not provide any audio signals. You will need to use conventional audio cables from your computer’s speaker/headphone output to your speakers or monitor with built-in speakers.
HDMI and DisplayPort interfaces provide digital audio as well as video., so you only have to connect one cable to your monitor or TV and built-in speakers will work.
Note that Windows will treat the digital audio connection as a separate sound device. If you have no audio you may need to go in to the Windows settings and select this device instead of the computer’s ’sound card.’