Screen Flickering - Windows 10 Hp Proone 600 G1 Aio

Computer: HP ProOne 600 G1 AiO
OS: Win 10, 64bit, version 10.0.19045 bild 19045
Behavior: From time to time the screen is flickering. Not in a specific area. Sometimes more obvious, sometimes lower flickering effect. There are periods of hours when it works as it should.
I installed the manufacturer driver but the situation did not change.
I tried identifying if the problem is software or hardware. I am convinced now that it is not software. Besides the new driver installation, I connected to that computer through AnyDesk and I can see the screen all the time without flickering (while the person there see it flickering).
So, I suppose a bad connection between the graphic adaptor and monitor. The monitor itself may have a problem, but it looks (at least, for me) that it is more probable to be a week connection (problematic cable), since it works well for hours, also. But I may be wrong...
I could not connect another monitor to the computer because its connector is of type DisplayPort. I will buy a converter DisplayPort do HDMI, but not right now...
I would like pieces of advice (basically) about this part of splitting the problem cause (wrong connection or monitor itself, inverter etc.).
Of course, if you think that something else is good to be checked, I will also try your suggestions.
Any other idea about solving the issue will be much appreciated.
Then, I could not find on the internet video clips where to locate the video adaptor and the cable connecting it to monitor. I could see how the cover can be removed and could see components (and some cables) without being able to understand which is which. I could not find a service manual for this computer.
So, an idea about the graphic card location, its connector to monitor and the the other end of this cable (on the monitor) I think will be a good start. Firstly to check if the connectors have a problem or the cable itself.
Anything else you suggest I need to check, will also be much appreciated.
Thanks in advance!

 

There is no reason to suspect a connection problem UNLESS the connection was not securely fastened in the first place, or sometime after hookup, the cable was somehow damaged through abuse, or puppy-dawg teething.

Running fine through AnyDesk only tells us the problem is with host computer's graphics solution or the monitor. You need to determine which. So you need to swap in a different monitor and see if it flickers too.

If a different monitor flickers on this computer, its the graphics solution (card or integrated), or, maybe, a power supply (PSU) problem. If this monitor flickers on a second computer, then its the monitor.

If you don't have a second monitor, note that most TVs made in the last 10+ years support computer input.

As for the PSU, graphics solutions are often the most power hungry devices in our computers. If the supply is beginning to fail, I would expect the computer itself to start having intermittent freeze, shutdowns, or reboots - but not always. A flakey PSU can really result in odd, seemingly unrelated problems. Is the computer stable otherwise?

Wait! Sorry! I just checked your specs again and see you have an AiO. That changes a lot since an AiO is essentially a laptop strapped to a desktop monitor. You will not be able to try this monitor on a different computer. But you typically can connect a secondary monitor to the AiO. I recommend doing that to see if it flickers too.

Being an AiO makes the possibility of a loose connection even less likely.

 

Firstly, thanks for your answer!
Then, when you say „Running fine through AnyDesk only tells us the problem is with host computer's graphics solution or the monitor.”, should I understand that AnyDesk does not use the computer graphics card? If it uses it and no flickering appears, doesn't it mean that the graphics card/solution on the host computer is OK?
I also wrote above that the computer itself has the video type connector of type DisplayPort (DP) and theoretically I am be able to try a different monitor for this computer. As I wrote, I do not have a cable with such a DisplayPort connector (and HDMI or even VGA to the other end). I will buy a DisplayPort-to-HDMI adapter, but not today... I thought to be it just in case, if I will not be able to find the flickering problem. I thought that seeing not flickering image remotely the host computer graphics card should be OK. Am I wrong?

 

To make sure we are on the same page, in remote access, the host is the computer that is being accessed remotely.

So the host will used its graphics card to display on its monitor. The remote computer gets its information over the network and then that is displayed on the remote computer through its graphics.

Yes, you are wrong. Remotely, you are not viewing the same "signal" as being displayed on the host computer. You are seeing the same "image", but you are receiving it over the network connection, not from the host's graphics.

So Windows on the host machine is, in effect, sending two graphics data streams, one to its own graphics solution then out to its monitor. The other stream is being sent out over the network where your remote then sends it to your graphics card and then to your monitor.

 

So, I must hurry up the acquisition of a DisplayPort-to-HDMI adapter, in order to better diagnoze where the problem is...

 

But how AnyDesk is able to create a digital image of the host desktop, without the host graphics, and send it on the network (trough AnyDesk) to be processed on the computer making connection? I thought that host's graphics card creates a single digital image of the desktop in its frame buffer and sends it to monitor and AnyDesk, too. Do you mean, Anydesk has its own graphics able to create the digital image/signal? Doesn't it "grab" image data directly from the host GPU's memory before it ever reaches that physical cable or monitor? And not (only) after that, AnyDesk encodes this data and sends it over the network to the other computer? Are you sure about what you say?
I am not an expert in this field and I only make suppositions which look logic to me. Of course, they can be wrong...

 

Because the OS on your computer tells the graphics solution on your computer what to display. The graphics solution takes that information from the OS then configures it to display on your monitor, based on the size and resolution of your monitor.

But with AnyDesk, instead of (or maybe in addition too) the OS also sends that display information over the network to the remove computer.

AnyDesk is NOT communicating directly with the graphics solution. It communicates with the operating system and it, in turn, sends the image data to where it needs to go. That typically is the graphics solution but could be the network card. In some cases it could even be out via Bluetooth to a nearby TV.

No. Anydesk on the host computer does not know what size or resolution the remote computer's monitor is. In fact, Anydesk does not even know that on the host computer. That is the job of the operating system, not programs running on the computer.

 

Can you guide me to some documentation able to cover what you say? I like understanding such issues...

I asked AI about the issue and it answered:
"
AnyDesk does not "build" the image itself; it captures raw pixel data directly from the host device's graphics system. It acts as a high-speed pipeline for what is already being rendered on the remote computer.

Where the data comes from:
The DeskRT codec hooks into the host's operating system and graphics hardware to retrieve visual data:

• Operating System Display Buffer: AnyDesk requests the current state of the screen from the OS (e.g., via Desktop Duplication API on Windows).
• GPU Dependency: It relies on the host's graphics drivers being active. If the remote device has no monitor connected and the GPU "goes to sleep" or disables its drivers, AnyDesk may display a "Waiting for image" message because it cannot retrieve new data from the graphics buffer."

I know AI is not always reliable, but it fits better my logical assumptions. What do you think about that? Especially, about this idea: "it cannot retrieve new data from the graphics buffer"... The yellow highlight belongs to AI. I only copied the answer text. And only bolded, underscored some parts...

My practical experience, from this point of view, is limited but in all (three) cases my assumptions were confirmed. From some years, we (the company where I work) have 16 machines printing phone cases in different locations. Sometimes, these machines need reinstalling some applications and I remotely connect to them using AnyDesk. There were two cases when their screens were flickering and AdyDesk image did not. In both cases changing the touch screen, the flickering behavior disappeared. In a third case, AnyDesk image was flickering too. I changed the touch screen, only to prove that my supposition was correct and it was flickering. Reinstalling the driver did not solve anything, I had to change the machine computer video card and solved the issue.

Maybe there is a different explanation and I have built a wrong mechanism of understanding the troubleshooting process I am talking about. Two plus one cases maybe are not completely relevant. But it sounds also like a confirmed AI mechanism, no offence...

If you can send me a link (links) to documentation explaining the AnyDesk rendering mechanism as you describe it, I will be very grateful.
Or deeply explaining why things behaves like you say. I like learning...

Anyhow, next week I will buy a DisplayPort-to-HDMI adapter to give me the possibility to better diagnoze the problem, using another monitor.

Now, besides the above (mostly) theoretical discussion, is it somebody who dismantled such a computer and able to guide me where the connector(s) of the video card - monitor exists?
Thanks in advance!

 

All I can say is screen capturing is a totally different function from remote computer access. You seem stuck on capturing images. That is not what remote access does or how it works. Sorry - I've exhausted my capabilities.

 

I do not deny the theory behind your explanations... As I said, I am not experienced in this field.
I was only trying to check if flickering on the host computer screen and not flickering on AnyDesk remotely accessed could mean that the host graphics are OK.
I must confess that I still do not know.
Thanks for your explanations!
I will try finding more sources to improve my knowledge on the issue...

 

I'll rephrase what I said before then will have to leave it at that.

The operating system on the host computer sends the same display information to its own graphics solution on the host computer as it does through the network to the remote computer.

The remote software just allows the remote user to see the same display information that the host user sees, and usually even take control over the mouse and keyboard too. It is not taking screen captures, then sending that to the remote users. That would take a tremendous amount of resources, not to mention time.

This tells me the flicker you see is being caused by the monitor or the graphics solution on that computer. And you verified that yourself when you said you do NOT see the flicker when accessing that computer remotely.

 

OK, thanks!
But if I would see the flicker accessing the computer, what should I understand? Where the problem should be located in such a case?
Thanks again!

 

AnyDesk can use graphics data from the graphics solution post processing or using software rendering via Windows API (Application Programming Interface). Normally it uses the graphics solution, but it can change to one or the other without notifying the user depending on a host of factors. It is not a reliable solution for diagnosing issues with a host display. The only accurate way to test the GPU and primary display is to use a secondary display, such as a known good monitor or television using an HDMI port or in your case display port. Snag an adapter, and see if the cloned external display exhibits the same behavior. If it does not, I would then be looking at either potentially a ribbon cable connection on the system board or the physical LCD panel of the AIO itself. The actual display panel of the AIO is not user serviceable.

 

Firstly, thanks for your answer!
Then, today I received the ordered DisplayPort-to-HDMI adapter and connected an external display sharing the computer desktop. I instructed the operator using the respective computer to check if the external monitor flickers (or not) in the moment when the computer display does that. After such an event will happen he must inform me about the specific behavior. I spent there some time there, but nothing wrong related to flickering happened.
Now, I would like to clarify a theoretical issue. Since, as you say, AnyDesk grabs graphics data solution of the host computer, OR software rendering via Windows specific API. Can you explain how AnyDesk `decides` which of the two ways to choose? Then, reading carefully what you wrote, should I deduce that AnyDesk is able to display a correct image, even if the host graphics or its monitor (or connection to it) have problems? If so, should I understand that AnyDesk has technical solutions to correctly display the host computer desktop in any circumstances? I assume that the Windows specific API cannot have problems simultaneous with the two mentioned theoretical problems (graphics, monitor or connections to it). Would it be a wrong assumption?
If so, how could you explain the case (I already faced with a different system) when the computer display was flickering AND AnyDesk image, too? That time, I supposed that the monitor of the problematic computer was NOT wrong. Graphics were integrated in the computer main board and I deduced that there is the problem. I changed the monitor only for testing reasons and the flickering problem was still existing, as I was supposing. We received a new computer main board, to solve the issue. In the meantime, I received the information that my way of what I thought being a good diagnose, is wrong, in fact incomplete. Now, I would like to clarify (theoretically) what could happen in the described case? In what circumstances host computer monitor AND AnyDesk image flicker?
Thanks in advance!

 

Firstly, the computer in discussion got scared of the second monitor (just kidding...) and it didn't blink, anymore (for one day and half).
Secondly, I tried better understanding what's behind the scene in case of AnyDesk way of diagnosis. I cannot swear that my understanding is perfect, that's why I'm questioning it:

In order to make the video signal transmission more efficient, AnyDesk (AD) uses Desktop Duplication API. Sending only updated image data it is more efficient.
But now the question would be is it Windows able to build the screen without host computer graphics? And the answer (my answer) tends to be that it can't.
I understood that desktop screen is built through a collaboration between the software and hardware, managed by the Windows Desktop Window Manager (DWM). This composition happens on the GPU. If you have no graphics hardware (or no driver), the system cannot properly build this final desktop image and AD cannot connect, or shows a black screen.
Once the GPU has finished building the desktop image in its video memory (VRAM), AD needs to get a copy.
Instead of "taking a screenshot" (which is slow), AD uses the DXGI Desktop Duplication API to ask Windows for a direct pointer to the finished desktop frame already sitting in the GPU's memory.
The API provides "dirty bit" metadata, telling AD exactly which pixels changed since the last frame. This allows AD to only retrieve and transmit the updated regions, rather than the entire 4K image every time. But this is about retrieving efficiency. Which is/was not my concern.

So, I would conclude:
Because the screen is built by the GPU, the Desktop Duplication API requires an active graphics device to function. At least, part of it...
1. The GPU first renders the desktop into an internal buffer (VRAM). Only after this is finished does a separate part of the GPU chip (the display controller) convert that data into a signal for the host video port.
2. AD uses the DXGI Desktop Duplication API to copy the updated image directly from VRAM. Because it grabs the image before it reaches the potentially damaged physical output circuitry, AD bypasses the flickering. The physical port or display controller on GPU would be damaged.
3. If GPU Core, VRAM, or Driver have problems, the memory chips are failing, the actual data AD copies is already "problematic", so You will see the same flickering or artifacts in AD. As it (probably) happened once in my case.
Any opinion, even contrary to my understanding, will be welcome.
As I said, besides solving the problem, I would like understanding...

 

The algorithm will use whatever method it deems most efficient.

 

Yes, but the question would be: Is Windows able to build the screen without host computer graphics?