HDMI to VGA - External Monitor Not Detected

Question

I have an Acer Iconia tab w500 running Ubuntu 12.04 - The only output I have is an HDMI output so I bought an HDMI to VGA cable to connect it to my external monitor. It's not being detected by Ubuntu. Please let me know what other information you would like me to provide. Thank You!

Solution 1

It will not work since HDMI is digital and doesn't support analog signals.

You could use an adapter.

There are two kinds of DVI signals

DVI-I, which has both analog and digital output, and
DVI-A which has only the analog output

So if you hook in the VGA → DVI cable, the signal will be analog on the DVI-end of the cable.

Since HDMI is digital, it doesn't support analog signals.

Extracted from here.

Solution 2

The DVI to vga adapters are passive with no active electronics. The simply connect the analog pins available on some, but not all, DVI connectors to the appropriate pins on the VGA connector. If you have access to the proper DVI connector they work fine - I have used two of them under Windows for several years.

Connecting HDMI digital to VGA analog requires active electronics to convert the digital signal to analog.

An example of a dongle that does exactly that is the DINO DCA106-HV HDMI to VGA Dongle which is available at several well know Internet vendors. This dongle is specified to work with several versions of Windows - apparently without drivers.

The only question is whether it will also work with Linux, in particular Ubuntu.

If anyone has some actual experience with this device and Ubuntu I would be very interested in your results.

An additional fact that may be relevant, it is reported not to work with Apple OS.

Comments

[irumata]

Is it just a cable, or is there some electronics/circuitry/chip in the cable (like ebay.com.au/itm/…)

[artfulrobot]

Do you definitely mean HDMI? Sure you do, but as pl1nk says, HDMI can't be converted to VGA without clever electronics. Which made me think you might have DVI port because some of these support analogue and digital, and it's possible to get a straight forward connector for this. Using it gives me problems detecting resolutions but the display is detected.

[emf]

Sam, I know this is possible, so don't give up. Make sure your monitor can be detected: look at the output from xrandr to see if there's anything detected. at all. If not, your cable is not connected or not working

[Patrick]

Why does this cable exist then: amazon.com/Cable-Black-Video-Support-Necessary/dp/B002TUC64W‌​/… So HDMI to DVI works though right?

[pl1nk]

@SamHakes - If you read the comments you 'll see that it's not working. Check my updated answer.

[Jez W]

In fact from the product description it would seem that that cable works only one way, that is to say, VGA output port from video card -> HDMI input on screen; the first bullet point is "Your video card must support digital signal output through VGA port function". So if the cable used is an equivalent to this, it wouldn't work in Sam's case anyway (outputting via HDMI port to a VGA screen)

[emf]

I can confirm that adapters from HDMI -> VGA work on Ubuntu linux 15/16/17. I have dual monitors with a small cable adapter, allowing dual screen setup for my laptop.

[emf]

As in my comment below, I can confirm that it is possible to connect a second monitor VGA based monitor to your HDMI laptop/PC via an HDMI -> VGA adapter. I have this working currently