I am running a triple screen setup from my laptop (Dell XPS 15). One HDMI cable connected to the computers HDMI output, and the other two are connected to a dual HDMI to Thunderbolt (USB-C) adapter.

I have noticed that when the adapter is close to the laptop, it loses Internet connection: The Wi-Fi driver seems to completely freak out, it finds no networks, let alone connect to any.

Moving the adapter instantly solves the problem and whatever I was trying to load, pops up immediately. Thus I have deduced that it must be due to interference on the HDMI adpater.

I use my laptop for work so, it’s moved around a lot, which is why the “just make sure the adapter is far enough away” solution is a finicky one.

I am wondering if there is a way to shield/insulate the adapter more permanently?

I wrapped it in tin foil with 2 layers of insulation tape. Which has made a very small difference. Anyone out there know a decent way to insulate from cable interference?

  • 1
    I believe you have misidentified the cable causing the problem. HDMI should not be affected by RF noise. However, an improperly designed USB port can be affected by a WiFI. I would grab yourself a male to female type-c cable and attempt to place some distance between the adapter and the PC.
    – Ramhound
    May 2 '19 at 21:36
  • 2
    "Insulate" is the wrong verb; you mean "shield" (from electrical interference). "Tin" (more likely aluminum) foil alone is a poor shield. It needs to be electrically grounded to be effective. To be clear, is the laptop WiFi using an antenna built into the lid with the screen?
    – sawdust
    May 2 '19 at 22:21
  • You could put ferrite snap-on chokes on cables near the connectors. Your IT department might have some, or see amazon.com/20Pcs-Clip-Ferrite-Suppressor-Diameter/dp/B016XE2BS0/… for an example. May 3 '19 at 1:05
  • Thanks for the input. @Ramhound , yeah, I believe the *adapter might be causing the issue. I didn't mention: putting my hand between the adapter (not touching anything) and the pc is also an instant fix. So from your comment, I'm thinking that interference is being emitted from inside the adapter wherever the usb-c cable is exposed and routed to whatever supplies the two HDMI ports with data. Sound right? I didn't think about buying an extension cable, nice..
    – Zingers
    May 3 '19 at 7:28
  • @sawdust fair enough, shield makes more sense. And yes, the foil is aluminium, I wrote "tin" out of habit. After reading up a bit, it seems Dell does put the wifi antennas in the lid above the screen. Any suggestions for a more suitable shield around the adapter?
    – Zingers
    May 3 '19 at 7:35

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