Forcing HDMI output on Windows

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Chris.Geerdts

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I purchased an HDMI to VGA adapter cable and it does not work from my laptop

I suspect that the problem is that Windows does not maintain a video output on the HDMI output jack if it does not sense a connection on the other side. I am sure that if I can force Windows to maintain the HDMI output regardless of what it senses, the converter will work.

I am battling to find instructions on the internet as to how to configure this. It is easy to get the config for Raspberry Pi, but not for Windows.

Please can someone point me to this information - I have Win 8, but I am sure I can do my own adaption?
 
You must set the screen to external display isnt it?

FN + (Some key)
 
Hi Rickster. Yes, when you set to external the cable should work, but if it doesn't pick up a signal (or can't read the EDID) it stops outputting.

I am asking for advice on reconfiguring windows to force the video output regardless of what it detects
 
Try in your graphics card control panel ie. Nvidia/AMD Control Centre etc..
 
Those adapters aren't always compatible with all display adapters/graphics cards so you'd need to get it working first before forcing HDMI output, or you'd end up with no display at all.

Which is bad.

So let's start with specs, what graphics do you have? Intel GMA, Radeon or Nvidia?
 
Also is it active or passive? I cant see a passive one working. Digital - Analogue
A Powered converter HDMI to VGA should work.
 
psion said:
Also is it active or passive? I cant see a passive one working. Digital - Analogue
A Powered converter HDMI to VGA should work.
Click to expand...

Why not? The laptop is HDMI, the display is VGA. If it was the other way around you might need power, but HDMI is already powered.
 
TJ99 said:
Why not? The laptop is HDMI, the display is VGA. If it was the other way around you might need power, but HDMI is already powered.
Click to expand...

Because VGA has an analogue signal Where as HDMI has a Digital signal...
 
psion said:
Because VGA has an analogue signal Where as HDMI has a Digital signal...
Click to expand...

And that's why you have a converter. Monitors are not powered through a VGA port, you only need the data signal. HDMI digital signal goes in, analogue comes out.
 
Yes and that data signal is analogue, the complete opposite of digital... but getting a little thing with an HDMI plug on one side and a VGA plug on the other wont magically make it work, the signal itself needs to be converted so that said monitor can "use" it. Also said converter needs to send a conformation signal back to say it is accepting the signal (EDID)

There is no way this will happen without a powered circuit. Yes HDMI outputs 5 volts however it only has 0.05 amps this will not be enough to power a convertor

So if this is a cable with the different connectors on either end it wont work. That is why I am trying to determine what "Converter" the OP has?
 
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These converters are sold at many stores. I have not seen HDMI to VGA adapters that have external power, and they do work without external power. Also many of them do not have much identifying info on them.
 
TJ99 said:
Those adapters aren't always compatible with all display adapters/graphics cards so you'd need to get it working first before forcing HDMI output, or you'd end up with no display at all.

Which is bad.

So let's start with specs, what graphics do you have? Intel GMA, Radeon or Nvidia?
Click to expand...

Thanks. It's a laptop with the standard Intel (HD 4000).

I have another HDMI screen at home so I'm not worried about 'losing' my screen, and I can clone screens too. I just want to force the HDMI long enough to give this adapter a try

I read that one way of doing it is to connect the laptop to an HDMI screen, then put the laptop into sleep, then replace the adapter and wake it up. I'm sure there's a more elegant way though
 
Electron1 said:
These converters are sold at many stores. I have not seen HDMI to VGA adapters that have external power, and they do work without external power. Also many of them do not have much identifying info on them.
Click to expand...
They all work without external power, the HDMI port is more than enough to power a simple DAC. Post above is just blowing smoke.
 
Chris.Geerdts said:
Thanks. It's a laptop with the standard Intel (HD 4000).

I have another HDMI screen at home so I'm not worried about 'losing' my screen, and I can clone screens too. I just want to force the HDMI long enough to give this adapter a try

I read that one way of doing it is to connect the laptop to an HDMI screen, then put the laptop into sleep, then replace the adapter and wake it up. I'm sure there's a more elegant way though
Click to expand...

I don't mean you'll "lose" anything (apart from maybe your sanity). If you force HDMI output and it doesn't work, both your external screen and your laptop's built in display will be blank and you'll have no way of seeing what you're doing.

If you right click on the desktop you should be able to go into the Intel GMA settings, there must be something there about display detection, the ATI and Nvidia drivers have those.
 
TJ99 said:
I don't mean you'll "lose" anything (apart from maybe your sanity). If you force HDMI output and it doesn't work, both your external screen and your laptop's built in display will be blank and you'll have no way of seeing what you're doing.

If you right click on the desktop you should be able to go into the Intel GMA settings, there must be something there about display detection, the ATI and Nvidia drivers have those.
Click to expand...

I've searched all the menus and actually they are rather limited. That's why I've looked to mybb for assistance. I think the answer lies in an inf file or a config file, a registry change or something like that. It was easy to find the settings for a raspberry pie, but fiendishly difficult for windows.
 
Chris.Geerdts said:
I've searched all the menus and actually they are rather limited. That's why I've looked to mybb for assistance. I think the answer lies in an inf file or a config file, a registry change or something like that. It was easy to find the settings for a raspberry pie, but fiendishly difficult for windows.
Click to expand...

To be honest, it might be hard getting an answer for this, as it's pretty rare to find ancient tech that only has VGA ports anymore, so most people don't bother with converters.

Edit: post a link to the adapter you are using.
 
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psion said:
Yes and that data signal is analogue, the complete opposite of digital... but getting a little thing with an HDMI plug on one side and a VGA plug on the other wont magically make it work, the signal itself needs to be converted so that said monitor can "use" it. Also said converter needs to send a conformation signal back to say it is accepting the signal (EDID)

There is no way this will happen without a powered circuit. Yes HDMI outputs 5 volts however it only has 0.05 amps this will not be enough to power a convertor

So if this is a cable with the different connectors on either end it wont work. That is why I am trying to determine what "Converter" the OP has?
Click to expand...

Why would they make such a connector if it doesn't work? Obviously that would have been checked before making it.
 
The reason I need a converter is because in my business consulting and training I present at different venues and some have an old overhead projector which don't support HDMI or Wi-Fi connection.

I know it is possible and that gamers do it on TV sets - basically it's just over-riding one line in the HDMI driver init.

I think there's enough evidence on the web that a passive device can work, if one can force the output. I'm keen to prove it either way
 
You have to purchase active converter. Word 'active' has nothing to do with power as people suggested, but electronics inside converting digital HDMI signals to VGA standard.
Passive device don't include any electronics and rely on non-standard feature passing analog signals through the HDMI connector. As it is non-standard, many (newer) graphics adapters do not generate such signals.
 
sajunky said:
You have to purchase active converter. Word 'active' has nothing to do with power as people suggested, but electronics inside converting digital HDMI signals to VGA standard.
Passive device don't include any electronics and rely on non-standard feature passing analog signals through the HDMI connector. As it is non-standard, many (newer) graphics adapters do not generate such signals.
Click to expand...

Point taken and I'll certainly look for another device once someone knowledgeable has passed on the info I've requested. I must say the Raspberry Pi forums seem a lot more informed - the answer to this was immediately forthcoming. I guess the Windows guys have lost that "what's going on under the hood" curiosity we had in the early days of DOS :-)
 
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