HDMI to VGA problem

[Macro Device]

I'm using this thing to connect my ancient VGA-only display to the GPU:

It works with my GTX 970 like it should but doesn't work with RX 6700 XT (as in the display is never detected). Why?

And of course I tested a real HDMI monitor on the latter GPU and it worked as intended.

 

[Dr. Dro]

Some VGA monitors won't accept a signal from a digital source, and these super cheap adapters won't work with them. I've tested many HDMI to VGA adapters, not one of them worked. After that, I purchased some DisplayPort to VGA adapter cables from Dell which work with modern GPUs, at least it worked with the 4080 last I tried. Part number is 05KMR3, if you can source one, it will likely work.

 

[Macro Device]

Some VGA monitors won't accept a signal from a digital source

Why does it accept it from a GTX 970 then? The only changing variable is video cards and one works, one doesn't.

DisplayPort to VGA adapter cables from Dell which work with modern GPUs, at least it worked with the 4080 last I tried. Part number is 05KMR3, if you can source one, it will likely work.

Cheaper to buy a new FullHD monitor than this one.

 

[A Computer Guy]

Some VGA monitors won't accept a signal from a digital source, and these super cheap adapters won't work with them. I've tested many HDMI to VGA adapters, not one of them worked. After that, I purchased some DisplayPort to VGA adapter cables from Dell which work with modern GPUs, at least it worked with the 4080 last I tried. Part number is 05KMR3, if you can source one, it will likely work.

I've experienced the same thing. The Dell DP to VGA adaptor I have works fine. The others I have HDMI to VGA are hit and miss although my J5Create HDMI to VGA adaptor has an additional 5v input for some reason but I've never used that 5v input.

 

[Dr. Dro]

Why does it accept it from a GTX 970 then? The only changing variable is video cards and one works, one doesn't.

I have no idea, but my best guess is that the GTX 900 series cards have a RAMDAC, and the newer ones don't. It was removed with the 10 series and I think AMD removed it with or after the R9 Fury X. Odd that the adapter is so pricy over there, it was cheap when I got it a few years ago.

I've experienced the same thing. The Dell DP to VGA adaptor I have works fine. The others I have HDMI to VGA are hit and miss although my J5Create HDMI to VGA adaptor has an additional 5v input for some reason but I've never used that 5v input.

I've tried one with external power, made no difference. Was a waste of money in the end.

 

[Macro Device]

Odd that the adapter is so pricy over there, it was cheap when I got it a few years ago.

This particular unit doesn't exist even in the shadiest shops of Russia so the device itself is 15 bucks + 40 dollars logistics = easier to buy a true DP/HDMI screen.

 

[ir_cow]

You can buy Active and Passive adapters. Digital to Analog should always be "Active". So far those have all worked.

 

[Macro Device]

You can buy Active and Passive adapters. Digital to Analog should always be "Active". So far those have all worked.

This one is active.

 

[Bill_Bright]

Some VGA monitors won't accept a signal from a digital source

Ummm, that should not be an issue. VGA is analog so the monitor would NOT be receiving a digital signal - assuming the adapter is working properly.

I suspect the problem is an unsupported resolution or aspect ratio and/or unsupported version of HDMI. Sadly, like USB, forward and backward compatibility is not always a given. HDMI versions and standards have evolved over time. While most adapters are designed to work with older HDMI versions, there could still be compatibility issues with newer versions that could result in missing or distorted displays.

This one is active.

But is it getting the power it needs to do the converting? With no external power source, it must rely on power from the graphics card. Perhaps this second card is not supplying it, or not putting it on the pin the adapter expects it.

You might see if you can borrow or buy an adapter that comes with its own external power source and see if it works then. But as Dr. Dro noted, that is no guarantee it will work, especially when other compatibility issues may be the problem. So hopefully you can borrow one to see if it works instead of spending more money on a lost cause.

Please keep us posted. I am curious how this works out, assuming it does.

 

[Macro Device]

But is it getting the power it needs to do the converting?

No way to check it but since it does what it gotta do with the older GPU I'm assuming it's all because AMD never intended to implement proper HDMI. At least my research on the interwebs showed a lot of people had various HDMI issues with RDNA2, mostly related to 2.0 and older cable versions because of poor or non-existent backward-compatibility.

I am curious how this works out, assuming it does.

We ended up buying a DVI display and it works with the HDMI to DVI converter I already had in stock so case closed.

But I'm still interested in more workarounds.

 

[kurosagi01]

This was the only work-around I found that worked for my partner ancient Dell PC for work that only had 1 HDMI port and the other was VGA.
Essentially need another source to convert the VGA signal + "audio" via USB which then convert to HDMI.

 

[Bill_Bright]

it's all because AMD never intended to implement proper HDMI.

I don't think one could blame AMD - at least not without further investigation. They do not create the HDMI standards or protocols. Plus, we just cannot, or should not expect forever support for such obsolete, superseded (multiple times) legacy technologies.

 

[Macro Device]

forever support for such obsolete, superseded (multiple times) legacy technologies.

It's 2.0 VS 2.1 so calling it "obsolete" and "superseded multiple times" is at least stretchy.

I know AMD are not in a must to implement EVERYTHING but providing support for HDMI 2.0 devices on an HDMI 2.1 GPU sounds... very straightforward. Maybe it's just me not liking to walk an extra mile because the production team decided to only support the cutting edge stuff.

 

[Dr. Dro]

Ummm, that should not be an issue. VGA is analog so the monitor would NOT be receiving a digital signal - assuming the adapter is working properly.

I suspect the problem is an unsupported resolution or aspect ratio and/or unsupported version of HDMI. Sadly, like USB, forward and backward compatibility is not always a given. HDMI versions and standards have evolved over time. While most adapters are designed to work with older HDMI versions, there could still be compatibility issues with newer versions that could result in missing or distorted displays.

On paper, yea. In practice, seems to be another story. The HDMI to VGA adapters I got work with a LCD monitor that has a VGA input just fine, but they do not work with my CRTs - and it all seems to be linked to whether the GPU is capable of outputting analog signals natively at a first glance. Older cards that are known to have a RAMDAC work, newer cards don't. The Dell adapter I mentioned was the only thing that worked around it, and it has a DisplayPort, not HDMI in. Really, I don't have the faintest clue other than the fact that it's not that it just doesn't work, the display simply isn't detected as if it was never there.

I don't think one could blame AMD - at least not without further investigation. They do not create the HDMI standards or protocols. Plus, we just cannot, or should not expect forever support for such obsolete, superseded (multiple times) legacy technologies.

It's 100% not on AMD, as my issues were on NV to begin with. If anything, being on AMD should be helpful towards debugging this. The Radeon driver writes a log which contains the monitor history and EDID configuration in the Program Files directory, if memory serves me well it's the amdkmdag_dce.log file.

 

[Macro Device]

The Radeon driver writes a log which contains the monitor history and EDID configuration in the Program Files directory, if memory serves me well it's the amdkmdag_dce.log file.

The neat part is it's empty. It never recognises the connection, as if it never happened.

 

[Bill_Bright]

On paper, yea. In practice, seems to be another story.

And that was my point. These protocols often claim being forwards and backwards compatible (at the lowest speeds or bandwidth supported) but often are not compatible. It almost (if not entirely) is always because the maker of the device failed to ensure such forwards and backwards compatibility. It is not the operating systems fault if the hardware manufacturer fails to ensure their device (or device drivers) fails to comply with industry standards. Yet sadly, so many immediately blame Microsoft or Windows - unjustly.

 

[Macro Device]

Yet sadly, so many immediately blame Microsoft or Windows - unjustly.

I had no reason to because... I had no signal anywhere, not only in the OS. That's definitely either on hardware per se or on its firmware.

 

[Bill_Bright]

Agreed.

 

[anonuser57]

I have a seemingly identical adapter that should be just as old that works fine with modern Intel and AMD integrated graphics. I have also dealt with a lot of display adapters from display port and HDMI to VGA. Adapters can be flaky with one computer and monitor but not the other even though the computers are all the same model purchased at the same time and same for the monitor. Try unplugging the monitor from power unplugging the adapter and unplugging the VGA cable, then plugging everything back in again. Aside from that get a DP to VGA adapter throw away the packaging so so you can't return it, test the new adapter and then try the HDMI adapter again.