Long-term investigation of unstable input

[justflow11]

Not the first time at all, there are MANY people here - including myself - which fixed this by fixing broken neutral wiring, especially on old TN-C systems...we've been saying for so long that the problem is neutral impedance, neutral voltage drift and wrong neutral to ground potentials, and people still dream about some fictional "emi" and are buying emi meters...it's WIRING, not some fictional interference that jumps from PC to PC over air.

hah, then why isn't the problem fixed by the battery and the clean circuit? You did something that gave you a 5% improvement, which you mistook for a fix. But, it is ok, I really want people to move further and further away from the source of the problem.

The problem is literally fixed by battery, but you need to disconnect UPS from the wall which is pointless as it will turn off after ~5 minutes (as long as the UPS is still connected to the wall it will not work correctly as it would still use building's neutral wire as a reference, even if you set it to run on battery), and no in my case the problem is 100% fixed and not just 5% with a clean circuit and splitted tn-c into tn-c-s just for PC and monitor, it has been fine for 3 months already, now it works exactly the same as if i would have turned on oven or iron, or like it worked fine late at night, but now it works like that 24/7 regardless of other appliances turning on/off or time of the day

I think it also still uses the buildings ground wire if plugged in, not just the neutral, which could still carry some harmonics etc.

You did tn-c into tn-c-s just for pc and monitor, do you live in a house? Or you did separate neutral and ground just to the beaker panel in the apartment?

[MK92]

I live in an old TN-C apartment, only a new dedicated circuit which electrician installed just for monitor + PC + modem was split into TN-C-S at the panel, everything else in apartment still has just 2 wires

[fa1kk]

Small update:
Since I started investigating this, the transformer feeding my house has now been replaced four times.

The first three were on the same feeder. The newest transformer, which was installed in September 2026, has a Y/Zn winding and is brand new, having been manufactured in May 2026; prior to this, I had Y0 transformers.

This time, basically everything around the supply changed:
1) New transformer, around 2× closer to my house;
2) Different 35 kV substation;
3) Completely new 70 mm² line, with the last 20 m being 16 mm²;
4) Only around 5-7 houses on this new line;
5) Completely new cables and connections.

So the transformer, feeder, grounding, and upstream supply are all basically new.

And all of that changed nothing.

I also completely disconnected the house wiring and powered the PC through a separate line after the meter. I tested it both with my PE and without it. The overall problem remained.

And if there is anyone who has any ideas, I would appreciate any useful ones.

Anything related to the body, sweat, software-based, PC, BIOS, monitor, health issues, or perioperative stuff will be ignored completely.

[astroasis]

Small update:
Since I started investigating this, the transformer feeding my house has now been replaced four times.

The first three were on the same feeder. The newest transformer, which was installed in September 2026, has a Y/Zn winding and is brand new, having been manufactured in May 2026; prior to this, I had Y0 transformers.

This time, basically everything around the supply changed:
1) New transformer, around 2× closer to my house;
2) Different 35 kV substation;
3) Completely new 70 mm² line, with the last 20 m being 16 mm²;
4) Only around 5-7 houses on this new line;
5) Completely new cables and connections.

So the transformer, feeder, grounding, and upstream supply are all basically new.

And all of that changed nothing.

I also completely disconnected the house wiring and powered the PC through a separate line after the meter. I tested it both with my PE and without it. The overall problem remained.

And if there is anyone who has any ideas, I would appreciate any useful ones.

Anything related to the body, sweat, software-based, PC, BIOS, monitor, health issues, or perioperative stuff will be ignored completely.

None of us know. Moving UNPLUGGED electronics can effect how smooth my pc is lol. Its a radiated disturbance electronically