Dell D6000 - Screen Flickering
 

Hi,
this is my current setup:
- Notebook ASUS N580VD
- 3x monitor HP 24w (which I use at 1920x1080 resolution)

I bought the docking station DELL D6000 (as listed by the Products page in the DisplayLink website) in order to attach all the 3 monitors to the notebook, but I'm having a flickering problem.

The docking stations is attached to the USB-C port of the notebook.

The two monitors attached to the 2 DP ports are working w/o problems (I'm using a HDMI->DP adapter), but the one connected to the docking HDMI port is showing a very bad flickering which is annoying and also problematic.

In order to find the root cause of the problem I tried to connecting ONLY the HDMI port of the docking station (I removed anything else), but the flickering is still there.

Here a couple of video showing the problem:
- https://photos.app.goo.gl/Y63KRu6PoUnq8CRh9
- https://photos.app.goo.gl/ri3B1HCuoCDmro6f8
- https://photos.app.goo.gl/Bgb9xFQiG9x5aLDi6

I already:
- downloaded the latest driver from DisplayLink website
- updated the docking station firmware using the software provided by DELL website
- updated the notebook BIOS to latest version
- updated Intel graphic card drivers to latest version (downloaded directly from Intel website, which are newer than the ones provided by ASUS website)
- updated NVIDIA drivers (this I think they don't matter anyway...)
- updated chipset driver, downloaded from ASUS website

As mentioned, the HDMI port is the only one showing this problem. I tried different cables, different monitors. I also tried to completely change hardware (different notebook, different monitor, differente cable) but the flickering is always the same as shown in the videos.

Also, I tried a simple USB-C -> HDMI adapter to test the USB-C port of the notebook and is working very fine.

For the moment the only working solution I found is connecting 2 monitor to the DP ports of the docking station and one monitor to the built-in HDMI port of the notebook, by I'm trying to have a workstation with "one cable connect" (video, audio, lan, usb devices, ...)

Is this a known behaviour between docking stations and ASUS notebooks? (I'm wondering...), it is a very odd behaviour so I'm trying to understand if someone knows a problem like mine.
Maybe an hardware incompatibility that cannot be solved, I don't know...

I'm attaching you:
- "Cattura 1" which shows the version of DisplayLink driver
- "Cattura 2" which shows you the version on Intel graphic card driver
- "Cattura 3" which shows how Windows recognize the monitor attached to the HDMI port of docking station
- "Cattura 4" which shows the details of Intel graphic card
And finally... the Support Information provided by the Compatibility Check software

I already ran the "DisplayLink Compatibility Check" and there is no problems


Thanks

Hello Nicola,

Thank you for taking the time to report this issue.
However, the problem you are experiencing cannot come from our technology and we have no way of influencing that behaviour with our code.

DisplayLink is a semiconductor company and we provide one chip in the Dell D6000.
The Dell D6000 uses two different display technologies when 3 displays are connected:
- DisplayLink over standard USB for the 2 DisplayPort outputs,
- DisplayPort over USB-C Alternate code for the HDMI output. That's why HDMI is limited to 4Kp30 when in 3 display configuration when the DisplayLink chip does 4Kp60. That's also why the 3rd output is only available over the USB-C connector.

Your report is very complete and I recommend you contact Dell with it. The only change I would recommend is that you include the version numbers for the Dell firmware utility you used as it will indicate to them what version the other chips are using. I use Dock_D6000_FW_Updater_A02_73F77 with mine.

Kind regards,
Alban

Hello Alban,
thank you for your reply.

I already contacted DELL support (support available only by phone, which is difficult to provide reports) and they suggested me to simply return the imt and ask for a replacement.

But the thing is I'm getting the same behaviour with a totally different docking station (different brand) so I'm try to guess which is the problem here.
Different stations, differente monitors, different notebook, ... I'm having an hard time to find a common variabile between all my attempts, but i'm unable to find a working combination to starts with.

Maybe ASUS notebooks have a congenital incompatibility for their USB-C port, so any triple docking station will provides the same error?
I think the USB-C port itself is working fine because using an HDMI adapter the monitor does not show any problem.

At the moment I'm having only 2 working solutions:
- Using an external USB->HDMI graphic card, also attached to the docking station
- Connect the third monitor the built-in HDMI, adding one cable to connect while i leave the workstation and come back.


I confirm you I used Dock_D6000_FW_Updater_A02_73F77.exe for firmware update.

Nicola,

Would you have brand and model for the other products you mention?
The HDMI converter and the other dock more precisely.

Alternate Mode is about passing non-USB traffic on a USB-C plug.

I wouldn't say the issue would be general to all 3-head docks. For instance, the Dell D3100 has 3 displays through DisplayLink technologt... and if it works for your displays on the Dell D6000 I would expect it to work on the Dell D3100 as well.
You might also wish to try with another refresh rate on the HDMI: this could be enough to stop the flashing/flickering. This is a bit burried in the settings, let me know if you wish guidance on that (if so, tell me the Windows version so I can find a relevant article).

Kind regards,
Alban

I-Tec CATRIPLE4KDOCKPD

It is a simple adapter from USB-C to HDMI, sorry but there is not branding, model on the product which I can give you

I can see that this product is a USB-3 (not type-C), so I can understand that in this case I will not use the USB-C display support but all the video will be managed by the station itself.

I already tried, but my Windows provides only 60-59-50, and none of them are working (50 maybe is even worse)

My Windows version is 1803.

As additional test, I bought on Amazon an HDMI cable with triple shield, maybe can solve the problem. I will not wait for delivery and test this additional case.

Thank you Nicola,

The i-tec uses the same principle, and you can see the same 4Kp30 limitation on the HDMI output.

For the Dell D3100, you are correct. This is a DisplayLink only solution. It has a dual-chip design of our previous generation chip. It can do 1x 4Kp30 + 2x 1080p.
The displays are driven directly from the dock output.
The dock isn't a GPU so the computation is still done on the laptop GPU.

Unlike Alt-Mode which doesn't go through standard USB hubs, you can daisy-chain DisplayLink technology. Therefore, you could wish to keep the future-proof aspect of the Dell D6000, and add a single head USB -> HDMI adapter. That adapter could also be useful when travelling or in meeting rooms as well: conference room system input, projector, TV...
Your next machine would have USB-C Power Delivery for charging, and this isn't possible over USB-A.

Kind regards,
Alban

I tried connecting a StarTech USB32HDPRO adapter (USB->HDMI) to the docking station, for the most part of time it seemed to work fine, but one time all the monitor (notebook included) crashed, going all black and turn back on after few seconds. This solution was using 2 monitor connected to the DP ports of the station and one to the USB-HDMI adapter.

But this was made using the USB-C port, so because I will not use the HDMI port anyway, I can try the USB port itself, but maybe it is a throughput higher than supported by a single USB-C port

This is supposed to work properly.
I'm using a similar setup on my desk: Dell D6000 + Dell D3100, combining the same chips you have. You can switch to USB-A and see if behaviour changes.

There is more than ample bandwidth. We were demoing 8x 4Kp60 at CES last January over a single connection. The dock is dual 4Kp60. A single 4K is 4x FullHD... I'm running out of money buying 4K displays before I run out of bandwidth. The codec we have is adaptative, so even if bandwidth was to become scarce, we would squeeze the data more to make it fit.

The USB-C bandwidth here is identical to the one over the USB-A connection. The dock has a USB 3 Gen 1 hub for 5 Gbps. The reason it's not a USB 3 Gen 2 at 10 Gbps is because it didn't need it and would bring the cost up un-necessarily.

If you keep getting issues, please do use our customer support tool to gather logs (3rd link in my signature). I use the feedback to prioritise bug fixing in new driver/firmware releases.

Kind regards,
Alban

Maybe it was a coincidence, it has been days that i'm playing with drivers of various components in order to find a working combination.

I will now try to maintain the same configuration for couple of days:
- 2 monitor attached to 2 DP ports of docking station
- 1 monitor attached to USB->HDMI StarTech adapter, attached to USB port of docking station
- docking station attached to USB-C port of the notebook (or USB-A, if is giving problems)
and see what happens...

I will back to you next week with a further feedback.

I think I already added this log to main message, can you check if the same that you're asking now?


Best Regards

Hello again,
I'm back after few days with some positive news, but not all.

After I tried to the same D6000 station with same notebook but different monitors, I find out that the kind of flickering was different. Sometimes was almost solved, sometimes was really really bad, ...

Because the monitor was working fine with the solution USBC->HDMI adapter (so it was surely the docking presenting the problem) I tried to buy a different cable.
I bought a very high-quality HDMI cable "HDMI 4k 60Hz HDR | HDMI 2.0 a/b | 4K 3D UHD 1080p 3D HFR Ethernet | Full HD 1080p / ARC e CEC"
This cable is triple-shielded and it is certified for 4K. I know I'm using the port at 1080p, but it natively supports 4K maybe can be a hint....

Test 1) Well, with this new cable, the HDMI port of the station is working fine, w/o any flickering (for test1 i connected the dock to USB-C port of the station and only the cable to the HDMI port).

Test 2) I attached the second monitor, to the first DP port of the station (using the previous cable), and now I have 2 monitor working

Test 3) I attached the third monitor, to the second DP port of the stations (using the previous cable), and now the HDMI-connected monitor is flickering again.

This is somehow strange, it does not seem the problem to be to the port itself, but the amount of monitor attached.
Because it seems to a interference of some kind, I bought another 2 triple-shielded cables that I will use for others 2 monitors, and then I will see the result.

I will be back to you next week with this result.
For the moment, the first hint to solve to problem seems to be related to poor-quality HDMI cables.

Hello again,
I received the 3 new cables as mentioned, and for the moment there is no solution.

This is my current scenario:

| ASUS N580VD --> USB-C --> DELL D6000
|
|--------- Station HDMI Port --> HDMI Cable--> Monitor HDMI Port
|
|--------- Rankie HDMI ->DisplayPort 4K adapter --> Docking DP Port --> HDMI Cable--> Monitor HDMI Port

With this configuration, the 2 attached monitor are not flickering, and the third monitor works attached to the HDMI built-in port of the NoteBook.

Adding the third monitor

| ASUS N580VD --> USB-C --> DELL D6000
|
|--------- Station HDMI Port --> HDMI Cable--> Monitor HDMI Port
|
|--------- Rankie HDMI ->DisplayPort 4K adapter --> Station DP Port --> HDMI Cable--> Monitor HDMI Port
|
|--------- Rankie HDMI ->DisplayPort 4K adapter --> Station DP Port --> HDMI Cable--> Monitor HDMI Port

The monitor attached to the HDMI port of the docking starts again flickering.

So, if at start the problem of bad manufactured cables was one of the cause, it is partially solved. The problem now is using both DisplayPort ports of the station.

Hi again,
I'm officially out of ideas.

I also tried buying DP->HDMI "active" adapter (whatever that means) as suggested by some sites and tried the shortest HDMI cable (0.5m).

Always the same behaviour of flickering.

At this point the only working solution is using the 2 DP ports of the station and the built-in HDMI port of the notebook. The USB->HDMI graphic adapter seems to work bad, after some point all the monitor goes black and all windows position are resetted to notebook monitor.

Any thoughts on this?

Hello again,

The 3rd output is never using our technology so whether it works and fixing it, is not under my control, unfortunately. The chip we make that Dell uses in the box only has 2 simultaneous outputs possible.
When using 2 displays (DPx2, DP+HDMI) it all goes through us because of internal switches, when you add the 3rd display, both DP are connected to our chip, and the HDMI is driven by the laptop through a converter (like your USB-C to HDMI standalone converter you tried, because the laptop outputs DisplayPort Alt-Mode and standard USB, not HDMI Alt-Mode) and that's when it starts the flickering.

I don't understand your case of DP->HDMI active adapter.
A passive adapter means it's not really DisplayPort, it's HDMI signals disguised in DisplayPort connector (called DisplayPort++ or Dual Mode).
An active adapter means the adapter is generating an HDMI signal itself, so it's not driven from the dock or the computer.

Kind regards,
Alban

Hi AlbanRampon,
at this point I don't know what to think, I'm unable to find a common ground on all my attempts.

It seems to be random, at the end I tried:
- different notebooks
- different stations (2 different brands)
- different monitors
- differente cables

The behaviour is always the same, the HDMI connected monitor is flickering.

The only common variable here is that all the notebooks I tried are ASUS branded (I don't have other USB-C notebooks of different brands), but I don't know if this can be a cause of my problem.

I reviewed the thread, and will attempt to summarise.
StarTech USB32HDPRO adapter (USB->HDMI) is using DisplayLink technology as well.
So, from what I can see, when using any of the DL-3xxx, DL-5xxx, and DL-6xxx HDMI outputs, your monitor works properly. You have issues when using the Alternate Mode, and potentially with DisplayPort converter chip.

When all your displays flashed, it could be because of a driver crash. The notebook will blink as you change the desktop layout.
If you still have that adapter, I'd recommend plugging it to your docking station and use it to drive the HDMI monitor.
Should it crash again, we can look into the crash data to improve the driver.

Kind regards,
Alban

Thank you for your suggestions. I tried the StarTech adapter in the previous days, connecting it to the docking station, but also used by itself (only notebook monitor and one external with the adapter) with the USB port of the notebook.
In both cases after some time both monitors get stuck, after few seconds they became all black and the all the layout is resetted (all windows are moved to the internal notebook monitor).

I don't know... maybe the StarTech adapter is damaged, but at this point I'm willing to consider a problem with the Intel driver itself of the notebook, not any external device I can use.

From first tests with the StarTech USB3DOCKH2DP I just bought, I can say that all 3 external monitors are working fine, even with the notebook display enabled: https://photos.app.goo.gl/s5p6UEZcY5nW5Jnf8

The difference here is that is an older model which use only the USB3.0 port and not like the newer model which uses the USB-C port.

From Control Panel of Windows I can see that 3 monitors are managed by the external station (instead of 2+1 like other model) and only the built-in monitor is managed by the internal Intel chipset.


Also, just for test purposes, while the dock was connected I attached 2 additional displays on the built-in HDMI port of the notebook and on the built-in USB-C port of the notebook (with a simple adapter), and all 6 monitors are working correctly.

And in this case, 3 monitors are managed by the Intel chipset and 3 monitors are managed by the external station.

https://photos.app.goo.gl/T3P83vCFZzhnmH3FA


After all this tests and this success, I'm willing to consider an USB-C incompatibility problem or something related to the notebook hardware or Windows drivers.

I will try a couple of days with this station but for the moment is seems the problem to be finally solved.

I do have the same problem. The third monitor that connected via HDMI is flicking from time to time and it's really annoying.

I ended up connecting the HDMI directly to my labtop (Dell Inspiron 13 7370) which is shame as I bought D6000 to replace my D3100 just because I want to have a single USB-C connection to my machine :(

While I was trying differents USB-C docking station I was using 2+1 monitor as well (2 with the docking, 1 to the HDMI built-in port).
Now that I tried this USB docking station it seems that the problem is related to the USB-C functionality.
Have you tried the previous docking station using a USB->USB-C adapter?

No, I haven't tried with the adapter. The D3100 worked fine with USB3 port but it requires power line.

I thought that upgrading to D6000 would allow me to forget the power line and use only a single USB-C to connect to my machine.

Now I can get rid of power line but need HDMI instead :(

However, just a few days ago, Dell has updated the driver and it's less flicking. Hope they'll keep updating until the problem gone.

Hello nicola/nonintanon,

In 3 outputs and with HDMI, I wouldn't wait for DisplayLink driver update as we don't control that output in that case.
I would recommend checking you run the latest third party firmware: https://www.dell.com/support/home/us...-d6000/drivers

If you do already run that, I can help by reporting this to the manufacturer.
For this, only connect the monitor exhibiting the issue to the D6000 on the HDMI port, then connect the docking station using the USB-A adapter. That's to be sure the display is controlled by the DisplayLink chip.
Then, please use the diagnostic tool listed in the last link of my forum signature to collect the logs.
This will give all the monitor details so we can try and reproduct the issue in our lab and submit the report.

Kind regards,
Alban

Hi,
I'm now using StarTech Docking Station with USB3 (no USB-C) since several months and it's running fine with 3x HP 27" screens.

At the end all my "flickering" problem were related to ASUS hardware in relation with USB-C port (ASUS support told me that this notebook officially supports ONLY 1 external screen).

Maybe other brands do not have the same USB-C problem, but using USB3 I solved my problem.

I just wanted to say that I have a Dell D6000 dock, paired with my Dell Latitude 7490. I had exactly the same problem you described, where the monitor connected to the HDMI port would flicker even though the monitor, cables and laptop were fine.

I have also connected the laptop to the dock via its USB-C connection, and two monitors via the displayport, and 3rd monitor using the dock's HDMI port. As the tech support person mentioned, the HDMI port uses the special USB-C alternate mode which means it's driven by the Laptop's internal graphics card and something special in the dock that is NOT displaylink but a different technology.

In this setup, the monitor connected to the HDMI cable would constantly flicker. ONLY that monitor would flicker, all other monitors including the laptop's internal screen would be fine. At some refresh frequencies (Hz) the flicker was like a strobe light. At other frequencies it would just flicker the bottom half of the monitor. Either way the monitor was completely useless.

After the most recent Firmware update (June 2019) of this D6000 dock, provided on the Dell website that the tech support person mentioned, the flicker appears to have completely disappeared. I will report back if the issue comes back, but it appears to be fixed.

If anyone reading this is updating the firmware, be aware that for the flicker to disappear, you have to power cycle the dock AND you have to reboot your laptop. I'm not sure why but simply un-plugging and re-plugging the dock was not enough after the firmware update. A complete reboot was necessary for me.