Question Mystery problem with static ?

[CelticStatic]

Hi, hope I've got this in the right place.

I've been trying to diagnose a recurring static issue with my system for the best part of a year and am reaching my wit's end with it. The symptom of the problem while the system is running is popping and crackling through USB headphones. After shutdown my backlit keyboard flickers and there is sort of a "kickdrum" type low thump through the headphones.

I've eliminated as many peripherals as possible such that my setup looks like this:

The wall socket is a twin socket with switches. I've found that, once the flickering is visible, switching off the PC at the PSU or breaking the "loop" at any of the other shown spots stops the flickering. The monitor is normally connected to the PC via Displayport but I found removing this cable didn't kill the flickering.

Recently I've noticed the same issue with a work laptop on a similar setup which suggests the problem is not internal to the PC itself. An electrician has also replaced the wall socket, but declared the original one to be "ok" anyway. I'm also aware that by trying to kill the flickering after shutdown I may be treating a symptom rather than the problem, but I don't know enough about the hardware to say whether this is the case or not.

Sorry for the information overload, but if anybody has any ideas I'd be keen to hear them, as the system is currently effectively unusable.

Thanks

 

[Lutfij]

Welcome to the forums, newcomer!

Mind sharing what your wall outlet is? Tom'sHardware has a collection of people from all walks of life and regions which is why we ask for people's location for context. In your case, apart from the wall socket design, are you sure you have proper grounding in your crib?

On second thoughts, please list the specs to your build, like so:
CPU:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
Monitor:

 

[CelticStatic]

Welcome to the forums, newcomer!

Mind sharing what your wall outlet is? Tom'sHardware has a collection of people from all walks of life and regions which is why we ask for people's location for context. In your case, apart from the wall socket design, are you sure you have proper grounding in your crib?

On second thoughts, please list the specs to your build, like so:
CPU:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
Monitor:

Sure, I'm in Ireland so it ought to be a 230v 50Hz standard household outlet. Type-G 3 pin plug.

Specs are:

CPU: Intel i7 9700K
Motherboard: ASUS ROGSTRIX B360-H (this has been replaced with same as part of trying to resolve this issue)
Ram: 2 x 8GB DDR4 Corsair Vengeance LPX
SSD/HDD: Samsung 860 EVO 2.5 SSD
GPU: AORUS GTX 1080 Ti
PSU: Corsair RM650X (which replaced a CX 550M trying to resolve this)
Chassis: Corsair Carbide 400c
OS: Windows 10
Monitor: AOC AG251FG and Asus VG27BQ (in the setup in my diagram I was only using the VG27BQ for simplicity, however I found when the flickering started while using both monitors, unplugging the Asus didn't stop the flickering).

The work machine is a Lenovo P15

I should add that the system ran on this socket for 2 years without issue (apart from an unrelated manufacturing defect in the original GPU about 2 months after it arrived). With regard to grounding, the electrician thought there was no issue on the socket

The problems very roughly coincided with the arrival of a new sit/stand desk and a few months after the arrival of the Asus monitor. The desk is generally unplugged when these issues are happening though and I can't say with any certainty that the desk and the problem definitely coincided exactly. The new desk also resulted in a general rearranging of the setup so there were a number of variables there.

 

[Nigel Spike]

With regard to grounding, the electrician thought there was no issue on the socket

I would be wary of an electrician who "thinks" there is no issue with the grounding. He should be able to know.
Has this ever occurred on another wall outlet?

 

[CelticStatic]

I would be wary of an electrician who "thinks" there is no issue with the grounding. He should be able to know.
Has this ever occurred on another wall outlet?

Well he stuck a multimeter in it and one of those plug-in socket testers which showed no grounding issue. I have a similar plug in tester which also shows no grounding issue with the socket. He was insistent that the issue was not the socket.

I have tried running it with the laptop power plugged into a lead from a different socket but the monitor still running off the usual socket and that didn't resolve the issue. Part of the problem is I can't dependably reproduce it every single time so it's difficult to verify even when running it elsewhere.

I'll admit it does look like a grounding issue because touching the PC case does seem to have an effect on the strength/ frequency of the flickering, although it doesn't eliminate it completely. For the sake of ruling it out I'll run everything for a while off an extension running from a downstairs socket but it seems an unlikely candidate to me on the basis of the socket tests

 

[MJS WARLORD]

Take the back off all your plugs ( unless factory sealed ) and check that all the screws holding the wires are tight.
Are you wires coiled up to look nice and tidy .... thats a no no cos you can create something called a mains hum.
I would ignore the headphone thump as i get this from the base unit of my 2.1 speakers.
What type of flooring is your set up on and do you move about a lot in your chair as this can generate a build up of static without you realising it.
Have you tried running other house hold items from the same wall sockets to see if they do anything odd

 

[CelticStatic]

Take the back off all your plugs ( unless factory sealed ) and check that all the screws holding the wires are tight.
Are you wires coiled up to look nice and tidy .... thats a no no cos you can create something called a mains hum.
I would ignore the headphone thump as i get this from the base unit of my 2.1 speakers.
What type of flooring is your set up on and do you move about a lot in your chair as this can generate a build up of static without you realising it.
Have you tried running other house hold items from the same wall sockets to see if they do anything odd

Unfortunately the plugs are all factory sealed. Everything including the PC is on the desk which is on a wood laminate flooring. I don't roll the chair about much on it that I'm conscious of, space is pretty limited anyway, so it's just back and forth from the desk when coming and going.

I used the same socket for charging various devices and never noticed anything unusual with them.

 

[CelticStatic]

So I tried running my PC from a different socket and within an hour or so had the same issue, so I guess that rules out the socket.

I started testing what I could for grounding with a multimeter. I could get 0 to very low resistance readings from all the ports being used on the back of the PC to the ground pin at the PSU. Couldn't get anything from the USB on the front (only headphones are plugged in here). Got a reading from HDMI port to plug on the Asus monitor. No reading on the AOC monitor, but I have seen the issue occur without this monitor.