Strange PC issue. Monitor flickers when opposite side electric switches are touched.

Futureized

Futureized

High-Frequency
Level H
Hi there,
Having weird issues with pc over many weeks.
Noticed monitor flickering issues when electrical switches on opposite side of wall are turned on/off
Called an experienced electrician today (after 2+hours of trying everything, he unplugged all sockets, rechecked earthing, rechecked loose connections) who finally came to conclusions that PC has issues.

I have spare working PSU which can be tested. Any other suggestions?
 
Futureized said:
Hi there,
Having weird issues with pc over many weeks.
Noticed monitor flickering issues when electrical switches on opposite side of wall are turned on/off
Called an experienced electrician today (after 2+hours of trying everything, he unplugged all sockets, rechecked earthing, rechecked loose connections) who finally came to conclusions that PC has issues.

I have spare working PSU which can be tested. Any other suggestions?
Click to expand...
Does the Flickering Happen With Turning on and of , with all the switches like Fan , Ac , Lights etc or does it happen with specific switch ??
For fans it can happen , because a motor has a surge current or momentary Voltage transit caused by starting current inrush when the fan is started or speed is switched. If Possible Plug the pc and the monitor to a UPS and check if the problem persist .
This is due to Electromagnetic interference or Radio Frequency Interference. which happen not only with HDMI but also with dsub component,dvi etc video/ audio interference. be it analog or digital does not matter. Also Try using a shielded HDMI or whichever display Cable You are using .
 
These issues can be weird. I used to have a PC, which used to resume from suspend if anything in surrounding area was switched on/off. Changed the motherboard, it did not help. Changed the PSU, it did not help. Many years later I changed the battery in the UPS, and, voila, the issue got fixed.


So yes, try the spare PSU. Try with UPS if you don't have, or without UPS if you already have it. Using a long cable, try switches of another room. All of this separately for PC, monitor, and both.
 
It's normal, monitors are sensitive to electrical disturbances such as sparks. Replace those switches if you have issue otherwise it's fine to ignore.
BTW make sure there's no loose cables on the monitor itself, that'd be dangerous and could be fatal to the monitor.
 
And my speaker used to do thud-thud sound whenever I used to turn on the ceiling fan or change regulator but this in my old house. and rarely few lines used to jump on monitor.
 
NanditaRoy said:
Does the Flickering Happen With Turning on and of , with all the switches like Fan , Ac , Lights etc or does it happen with specific switch ??
For fans it can happen , because a motor has a surge current or momentary Voltage transit caused by starting current inrush when the fan is started or speed is switched. If Possible Plug the pc and the monitor to a UPS and check if the problem persist .
This is due to Electromagnetic interference or Radio Frequency Interference. which happen not only with HDMI but also with dsub component,dvi etc video/ audio interference. be it analog or digital does not matter. Also Try using a shielded HDMI or whichever display Cable You are using .
Click to expand...
Specially with fan only.
Don't have ups to check though.
Monitor is connected via HDMI
Yes will give other PSU A try.
Those are 1000 and 750 watts from corsair
nRiTeCh said:
Test on that psu if electrician said alls well...
Click to expand...
Ordering and trying on new power cables as well, existing cables are almost 8+ years old.
Any suggestions for 2 good power cables from Amazon?
 
NanditaRoy said:
Does the Flickering Happen With Turning on and of , with all the switches like Fan , Ac , Lights etc or does it happen with specific switch ??
For fans it can happen , because a motor has a surge current or momentary Voltage transit caused by starting current inrush when the fan is started or speed is switched. If Possible Plug the pc and the monitor to a UPS and check if the problem persist .
This is due to Electromagnetic interference or Radio Frequency Interference. which happen not only with HDMI but also with dsub component,dvi etc video/ audio interference. be it analog or digital does not matter. Also Try using a shielded HDMI or whichever display Cable You are using .
Click to expand...
Second this. Try it with a UPS.
 
Have a similar issue with my monitor (Lenovo L series 24) but only when the generators kick in. I'm using a UPS as well. However, my brothers display (LG 22Mp68Vq ) doesn't :/
 
Check HDMI cable (if not using same that arrive with Monitor in box), I have had issue with Generic HDMI Cable (used 3 different local brand and all 3 have same issue).

I again start using original cable that got with Monitor and no issue so far.
 
NanditaRoy said:
Try with a voltage stabilizer if UPS is not available .
Using a good quality shielded HDMI cable surely does help
Click to expand...
Hdmi cables seems new.
Came with old 2nd hand monitor.
Futureized said:
Specially with fan only.
Don't have ups to check though.
Monitor is connected via HDMI
Yes will give other PSU A try.
Those are 1000 and 750 watts from corsair

Ordering and trying on new power cables as well, existing cables are almost 8+ years old.
Any suggestions for 2 good power cables from Amazon?
Click to expand...
Got this cables too. My hardware is already 10+ years old. Completely unsure what can be faulty.

Gizga Essentials Laptop Power Cable Cord- 3 Pin Adapter Isi Certified(1 Meter/3.3 Feet) https://amzn.eu/d/2KP52TS
 
Last edited:
Futureized said:
Hdmi cables seems new.
Came with old 2nd hand monitor.
Click to expand...
I don't remember exactly which cables, but if they are the flat ribbon-like HDMI cables then they are not shielded and are a bit long as well.

If you have an electrically noisy environment, the best HDMI cables for you are:

1) as short as possible for your application
2) not flat but round (twisted cables pick up less noise)
3) shielded as per the manufacturers description
4) with ferrite cores at one or both ends
 
salian said:
I don't remember exactly which cables, but if they are the flat ribbon-like HDMI cables then they are not shielded and are a bit long as well.

If you have an electrically noisy environment, the best HDMI cables for you are:

1) as short as possible for your application
2) not flat but round (twisted cables pick up less noise)
3) shielded as per the manufacturers description
4) with ferrite cores at one or both ends
Click to expand...
Thanks @salian .
Can you provide amazon link to purchase same.
HDMI called can be required anywhere, will go with good quality
 
51QJpskwcfL._SL1200_.jpg
Something like this, short, round and with ferrite cores, should be most noise-resistant.
Couldn't find that exactly on amazon, but perhaps this or this?
 
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