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Most of our school is still using VGA for projection. We would eventually like to go to HDMI but that is going to take at least a couple years. The laptops (HP Elitebook 850 G5) we are getting from the Ministry of Education only have HDMI ports now so we are using HDMI to VGA adapters.

The problem is that (in many areas) we are finding that when using an HDMI to VGA adapter the image is cutting out for a few seconds every 10 seconds or so. It doesn't seem to matter what model projector is in use (there are several). We have tried a couple of different adapters and can't pin down the cause.

Here is the adapter that we most commonly use:

Are there some really expensive adapters we need to make this work reliably? Is it just not a good idea to use HDMI to VGA adapters at all? Is there even a difference between adapters? Why do some of them cost a lot more than others?

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  • HDMI is digital. VGA is analog. The only way to convert HDMI to VGA is with an expensive, converter. Unless, the video card on the computer supports VGA over the HDMI port, in which case a cheap passive adapter will work. That is the difference in price. Have you tried adjusting any display settings or updating drivers? What make/model of laptop are you using? Mar 26, 2019 at 0:51
  • Hey Appleoddity. It is a HP Elitebook 850 G5. I can't find any information on if the video card supports VGA over HDMI.
    – MattMack
    Mar 26, 2019 at 1:18
  • I use a low-cost HDMI-to-VGA converter like this one: amazon.com/CableCreation-Converter-Audio-Adapter-CD0058/dp/… without any issues. It has an Explore EP9851 HDMI-receiver-to-analog-video chip that supports HDCP 1.2. With it I can connect a Blu Ray player to a projector with RGBHV inputs. Note that this converter requires an external 5V power supply.
    – sawdust
    Mar 26, 2019 at 4:25
  • The HDMI to VGA adapters I've seen were reliable only at 640x480 and 800x600 resolutions. At higher resolutions they smeared, ghosted and occasionally flickered. So ... if you are using higher resolutions than this, you might try decreasing the resolution to 800x600 and see if things stabilize. If that does solve the problem, then (since 800x600 probably is not what you would like) you'd need to shop for a more reliable converter.
    – user702986
    Mar 26, 2019 at 4:32
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    That's not true for every HDMI-to-VGA converter. I use mine for 720p (i.e. 1280x720) without issues. Note however that I'm using a CRT projector, which can be configured for almost any resolution and timing less than its max bandwidth. The general rule you'll have to follow is use a resolution that is common to both VESA and video standards. BTW you've framed your post to blame the "HDMI to VGA adapter" that you're using. But you neglect to mention salient details like what resolutions the projectors accept, and what resolution you're sending.
    – sawdust
    Mar 27, 2019 at 1:07

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I'd try using a different adaptor, just something off amazon like this:

If that doesn't work you may have to buy more expensive adaptors as VGA is quite an old connection (analog) , whereas HDMI is far newer (digital). If neither of those work try updating display drivers if you can, but as they're government issue laptops, I doubt you will.

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