CAP

Hi!

Since your devices work well in one place and poorly in another, this narrows the search to AC problems.

First: what kind of electrical system do you use at work? Is there grounding? What kind of system do you use at home? I mean TN, TT, IT systems.

Second: your laptop most likely does not have a grounding contact in the power supply, so it is grounded to the monitor, and if there is grounding at work, but not at home - this may explain.

Third: both the desk at work and the desk at home have a metal base. The desk at work may be far from the walls from which AC interference comes, and on the contrary, the desk at home may be close to the wall, behind which there is wiring.

I will explain why this is important:

The metal absorbs interference from the walls and then this radiation goes to the devices located on the table. Even if your devices are grounded, interference will still penetrate from the metal base into your devices. To fix this you need to ground your table: connect the metal leg of the table to the ground contact in the socet.

fourth: AC has harmonic distortion. Different networks have different harmonics at different frequencies, and no one knows yet which frequencies affect our heads. (presumably the strongest influence is the low frequencies 100-2000hz)

Perhaps the electricity at your work is cleaner than at home.

  • CAP replied to this.

    Slender

    Thanks for your reply.

    I will try to find out about the grounding systems in both places and see if it is different.

    My desk at home has wheels so I sometimes work in different locations in the room, far from the wall and I get dizziness too.

    Would it help to have a grounding cable attached to the legs of the table?

      CAP

      you need a cheap chinese emi tester like wt3121, if your monitor shows higher than >0mV, it means there is something wrong with the grounding.

        Slender chinese emi tester like wt3121

        what freq range do we need exactly to measure, is EMF meter is enough?

        1. For example, PC monitor's fields, and what happends if I turn-on XMP profile in DDR4 (2133mhz, 3200mhz) - what freqs do I need to catch
        2. Mobile phone, laptop, chargers - what freqs

          simplex

          It is necessary to distinguish between the interference (emi field) caused by AC and the frequencies that are in the emi field. External emi can be measured with a device such as wt3121 (as shown in the photos at the beginning of this thread).

          frequencies can be measured with an oscilloscope.

          What's the problem?

          Even when your monitor will not emit any field (0mV), (at least that wt3121 sees), bad frequencies will still be emitted from your pc, monitor, walls of your house.

          The AC emit itself will always be present, that's physics. Only harmonics within this field have an effect.

          I don't know what frequencies exactly are projected when increasing the voltage of system components (cpu/ram/gpu)

          Slender
          Hope you understand that the "chinese emi tester" you're using is a glorified AM radios (at best) which isn't calibrated for measuring the necessary range you're trying to target, spouting random values.
          Take a look at this review for more information
          You're supposed to use a proper spectrum analyzer from reputable brands such as LeCroy, Keysight, Rohde & Schwarz, Tektronix for this type of troubleshooting, especially when approaching the 2.4–5GHz range.

            5 days later

            qb74

            yes i understand that. And yet it showed a problem. In my case the interference was breaking through to the pc from the metal table. And this is despite the fact that my pc was grounded. I still got 25-35 mV from the monitor screen and the pc. It was very interesting to discover this: I touched the pc case with my hand and the table leg with my foot and saw how the values ​​dropped to 0.

            simplex
            his build:
            7600x
            32 gb gskill cl28
            klevv cras c930 m.2 1tb
            gigabyte 4060 ti 8gb eagle
            asus PRIME B650M-A AX II
            antec c5 case white
            cx750m 2024

            All components are new, retail os system.

              Slender All components are new, retail os system.

              Interesting

              New build dont have issues for 100 prc?

                Slender

                I got a wt3121 and my monitor is 0 mV. Near the laptop it is in red but low amount. I noticed that some walls of the room and especially the ceiling can go up to 300mV

                  simplex

                  sorry i dont know about eye pain for him but he had problems with graphics, input lag, image jitter, blurry, desync.

                  Perhaps it helped that he reduced the system consumption by half, compared to the 14700k and 3080 he had before, with the same PSU wattage (750w).

                  CAP

                  if your monitor has no emit, it means that it is grounded. Without connecting the laptop power, does it emit? Laptop shows some values when monitor (hdmi, monitor power) / laptop power disconnected?

                  • CAP replied to this.

                    CAP I do not have an explanation, but I share a similar story. All the screens that started bothering me were used at home, specifically in one area where my desk is. At work I had far fewer issues, but when I took screens from work to try at home, then they started bothering me in both places. I do suspect some kind of electrical, grounding, or emission problem in that area at my home that made me sensitive to those screens.

                    Slender

                    I have done some more tester readings and now the screens shows some mV, depending on where I am located in the room but in the place where I work the monitor shows low activity, like <10 mV. If I move the computer table and I sit on the sofa the tester goes to >100 on the scren.

                    When I connect the monitor to the table PC, on the same table, the monitor show >40

                    The laptop show as well some some value both mV and uT.

                    dev