Bizarre video drop-out problem - eviltoast

I am experiencing a technical issue that I can’t even explain, let alone fix.

Short Version: My laptop’s video link to our television regularly drops out for 10-15 seconds when anyone steps too heavily on a particular area of the floor.

Long Version (because I don’t know which details might matter):

My wife and I regularly participate in video meetings with friends, so we have a setup for it in our living room. My laptop serves as the computer. It is connected to a Thunderbolt 4 hub on a side table to the left of my easy chair.

There is a video adapter connected to the hub. 20’ HDMI and USB cables run along a wall to the left of the table to connect the hub to the television and the camera that’s mounted on it (Logitech Brio 4K). Another 20’ USB cable runs behind the chair and forward along the right side where it connects to a microphone (Logitech Yeti X). The microphone is on another small table that extends out into the room just in front of the chair arm.

My wife uses an easy chair immediately to the right of mine. The microphone wire runs between the chairs, but does not touch either. None of the cabling or devices are in front of, behind, or to the right of that chair.

The problem is that when my wife gets up, the tv picture often goes black for 10-15 seconds. The television indicates that it no longer has a signal during that time. Then the picture comes back and things return to normal. During that time, the camera and microphone both continue to work normally.

The drop-out happens when she puts weight on the floor immediately in front of the chair, not when she puts pressure on the chair to get up.

Occasionally the drop-out will happen when one of our dogs (50-75 pounds) jumps down from the chair onto the same area or when someone walks across the area. The section of floor where this happens is no more than a couple of feet square, starting at the front of the chair and extending out in to the room. There are no cables or wires in the immediate vicinity on the floor and there is no electrical wiring under that section of floor.

We have speculated about static electricity, but there is no obvious way it would get into the microphone wiring across at least an 18" gap. I also replaced the microphone’s USB cable with one that is better shielded, which made no difference.

So what could cause the video signal to drop-out when someone puts weight on a section of the floor with no apparent connection to any part of the system?

Any theories or suggestions would be welcome. We are genuinely mystified.

  • Curious Canid@lemmy.caOPEnglish
    1·
    9 months ago

    Further Information

    I have now gone through more of the troubleshooting process:

    1. I replaced the HDMI cable with one that has better shielding more bandwidth.
    2. I switched all of the data cables, at both ends, to different ports.
    3. I removed the hub from the equation and connected the video directly from my laptop to the television.

    None of that fixed the problem.

    On the negative side of the testing:

    1. I verified that my camera is not affected by the problem. The camera sits on top of the tv and it’s cable runs right next to the HDMI video cable all the way from my laptop to the tv.
    2. I tested everything for susceptibility to vibration by shaking the laptop, television, and cable. I was unable to reproduce the problem that way.

    I don’t have direct access to the underfloor of that room, but I do have access between that room and the breaker box. All the wiring goes in along the outer wall, so I doubt there is anything running under the middle of the floor, which is where the problem gets triggered.

    The more possibilities I eliminate, the stranger this gets.

    Can anyone suggest more things to try? Or propose a theory for how this is happening?