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I have recently set up a docking station at home.

It works great when I connect my old desktop and my newer Lenovo T490 laptop.

However we have a work PC that I would like to connect as well, but we have run into several problems. The laptop is a HP Elitebook 840 G5 with (I believe) a thunderbolt 3 port.

Description of the problem

When connected for the first time, everything worked as expected for about 20 min then the video signal suddenly went away. All the USB peripherals kept working and the laptop was still charging (from the PD in the dock).

We tried connecting one of the displays directly with HDMI - this didn't work either so we thought some piece of hardware was fried.

The IT department tried resetting the PC and surprisingly external graphics were restored. But after about an hour in the docking station the screens suddenly went blank again from missing signal (and the HDMI port stopped working just like the first time - exactly the same situation).

The IT dept has said don't do that again after a second reset, but I really want this setup to work.

Question

How can I get the HP laptop working consistently with the i-tec docking station? What went wrong and how can I prevent it?

Alternatively - how can I restore external video when this happens, preferably without a hard reset. Any kind of explanation would be great. I'm not too keen on testing different solutions while I don't know what's happening and how to fix it (and I can't reset the machine myself - it has to go through the IT dept.).

The hardware in question for reference

Laptop: https://support.hp.com/gb-en/document/c05903000
Docking station: https://i-tec.cz/en/produkt/c31tripledockpd-2/

What I've considered so far

This error is mostly a mystery to me - compatibility between HP laptops and third party docking stations are rarely considered in what I have been able to find. But since the port is a generic TB3 port and the fact that it did work in a limited period of time supports the case that it should be able to work consistently and that the problems are software related.

The i-tec docking station has some included software, but it seems to be only backup tools and the like. I haven't tried installing it since I can't think of a convincing argument that it should work.

The dock in question has Power Delivery up to 85W. Our electric outlets are not grounded (old house and installation) and we have gotten a few shocks from the tip of the USB-C cable itself and from the metal casing of the HP when it is connected when we accidentally ground ourselves of the nearby radiator. Could there be some security measure in the laptop disabling external video when registering a surge of this kind? If this is the case can anything be done about this without rewiring the house?

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  • Can you tell us, if you did something about the drivers? Not only for the docking station but also for your laptop. Have you tried installing the drivers for the dock station on the 1st place? If the problem persisted, did you check your TB3 drivers on your laptop? Aug 24, 2020 at 16:23
  • No, I just have just plugged it in. On my other (private) systems this ‘just worked’ on Windows and Linux. Since the HP is a work laptop I have limited access to fiddle with drivers (I think we can apply for administrative rights, but I’m not sure yet - the machine belongs to my spouses workplace so I haven’t had direct contact with the IT dept.). It seems plausible that the TB3-drivers could be in need of an update, but then again the system does work - for a time. Is it possible to check the drivers without admin rights?
    – glaux
    Aug 24, 2020 at 16:58
  • This is possibly caused by the build-up of static electricity, which is perhaps supported by your account of an electric shock. Try grounding the laptop and dock by a wire to the radiator (which I gather is nearby and grounded).
    – harrymc
    Sep 9, 2020 at 9:06
  • @harrymc That's what I'm afraid of. I'm not sure that the radiator is properly grounded (it's an apartment building on the first floor - I risk giving my neighbors an electric shock if I connect the chassis to the pipe).
    – glaux
    Sep 9, 2020 at 9:28
  • I don't think the electricity will accumulate on the radiator, and you can always test it by touching it yourself. In the future you could look for a better solution.
    – harrymc
    Sep 9, 2020 at 9:31

1 Answer 1

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+50

Your account of the time it takes for the problem to appear and the fact that you got an electric shock, seems to support the theory of a build-up of static electricity on the motherboard and/or on the video card.

As a temporary solution, try grounding the laptop and dock by a wire to the radiator (which I gather is nearby and grounded). The electrical charge should not be large enough to cause troubles with the neighbors.

If this helps, you should look into the earthing of your electric outlet, which is perhaps insufficient. You could also have a repair-shop have a look at your computer and its electric connections.

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  • @glaux: How did it work out?
    – harrymc
    Sep 15, 2020 at 18:58
  • I have just had a electrician create a grounded socket (because we were getting shocks anyway - and I was not too keen on making a temporary grounding). I'll test the problematic laptop in this new setup when we get home today in about 6 hours.
    – glaux
    Sep 16, 2020 at 9:15
  • The problematic HP has been connected a few hours now with no problems - and we don't get any shocks by touching the chassis. So grounding the socket seems to be the correct solution.
    – glaux
    Sep 16, 2020 at 18:03

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