#StackBounty: #laptop #external-display #docking-station #usb-c HP Elitebook loses external video signal after short time in a dock

Bounty: 50

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.


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?

Get this bounty!!!

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