Why my pc froze after switching the desk lamp or the speakers ON or OFF?

I'd like to know how it's technically possible that in the time period of few weeks my computer reacted to ON or OFF the desk lamp and ON or OFF the speakers. I tried to find an answer in pc forums but nobody could explain this sufficiently so I want to try it here becouse I think it's related even more to electronics forum. I had just connected two monitors to the pc and always in the evening (without exception every night for a couple of weeks) when I needed to use headphones and switched off the loud speakers my both monitors turned off (light indicator on both changed the colour from green to orange), the computer froze (caps lock light indicator on the keyboard didn't react) and the fans inside the case spun up to the max speed (I'm not sure if every fan, I only know that a graphic card fan did it). The pc was in this state until I reseted it. Then after rebooting I turned on the desk lamp and the same thing happened again. Before I went to sleep I turned off this lamp and if it was before turning off my pc it happened again.. Then in the morning when I turned on the speaker it happened again.. After that when I tried experimentally to switch on the lamp (which was pretty absurd when it was the light) nothing happened. So I switched off the lamp and it happened again. Together I guess it had to happen for at least 50 times (it wasn't a coincidence happening randomly)... Last time it happened when I returned from outside..it was exactly at the moment when I put my phone on the ground in my room. There wasn't any electronical reason from my side. Now it's alright. It stopped spontaneously without any intervention even I didn't change anything around my pc.

I had everything plugged into one power strip but I could run two pcs together there and it worked fine and the freezing thing was happening when I ran only one pc. That means that there was a reserve in power for higher load. So I think it wasn't the problem with low power from the wall. The desk lamp was with 11W fluorescent tube and was plugged into the wall (same the speakers). I'm sure it was happening even I didn't have anything else plugged into the same power circuit.

I have my pc still connected to the same power circuit and I have no problem anymore. Also the power supply still works fine in my pc.

I'm just curious how it is possible that my computer reacted this way.. What is the electronical bond between the lamp or the speakers and the pc? What could be the cause of starting the problem and stopping it? Thanks for any ideas.

Excellent writeup. Seldom i see that.

Your troubles could have been due to many reasons :

bad connections on power strip. something shorted in power strip.

bad power supply in your pc. Is it new ? refurbished ? what ?

bad monitors. In some way. That seems to be the only real change you made. Some grounding issue maybe.
Now that the problem has "gone away", did you disconnect either of the monitors ?

Lastly - it could of been a transient poltergeist. But thats very rare. Do you live in a "..aaAaaa... woooOooo.." kinda neighbourhood ?

cheers!

I agree with the previous post suggestions, but will add what type of power strip have you got.
I had problems with a 6 way block where slight flexing made the earth connection intermittent and I gues also caused some arcing at the power an neutral.

I took the block apart and inside were the power bus(es) made of bent metal formed to fit inline with the socket holes. The case was a flexible rubber material and when twisted made the power bus deform badly. I also tested this with a socket tester I had previously made consisting of mains rated neons across each of the three pins. It was 'shocking' (pun intended!) how often and easy it was for the earth to be seen to disconnect.

Power block into the bin. New rigid power block and then everything OK.

I know this doesn't quite fit your two PC working scenario, but that could be another symptom. I would suggest plugging the PC into the point closest the power feed to stand best chance of a good connection.

Can you provide any more information on your supply, such as are there known problems, could there be poor earths or no earths and anything else?

kripacharya and pinout thanks for your comments!

kripacharya said:

bad connections on power strip. something shorted in power strip.

Click to expand...

I'm still using same power strip and have no problem about it. So I don't think it's the case. And if it was shorted I think there would be power outage becouse fuse would switch and that didn't happen. Moreover it seems to be strange to me that pc would react in so complex way (switching off monitors, freezing, speeding graphic card fan up to max) only for power problems.. I would expect simply turning off the pc or reset. Only that the graphic card was in some safe mode which would start all these steps..is there such thing like safe mode for a graphic card?

kripacharya said:

bad power supply in your pc. Is it new ? refurbished ? what ?

Click to expand...

Even power supply (Fortron) still works fine three years later so I would exclude it. It was five years old when it was happening.

kripacharya said:

bad monitors. In some way. That seems to be the only real change you made. Some grounding issue maybe.
Now that the problem has "gone away", did you disconnect either of the monitors ?

Click to expand...

I didn't notice any problem with the monitors. It didn't start happening when I connected them both and didn't stop happening when I disconnected one. It wasn't dependent this way. I had both monitors connected for longer time and it started and stopped within that time.

kripacharya said:

Lastly - it could of been a transient poltergeist. But thats very rare. Do you live in a "..aaAaaa... woooOooo.." kinda neighbourhood ?

Click to expand...

I'm sorry but I don't understand what "..aaAaaa... woooOooo.." kinda neighbourhood means :-|

pinout said:

Can you provide any more information on your supply, such as are there known problems, could there be poor earths or no earths and anything else?

Click to expand...

Like I said my power supply is Fortron and I didn't notice anything wrong about it. The only appliance without earth bus is my speaker (power supply and monitor has it).



It's kind of mystery for me becouse everything works still fine so the failure of components can't be the cause. Also how could it start and stop of itself after few weeks?

One last thing: please if anybody know about somebody having same problem (it doesn't matter if in past or now), let me know and write about it here. I'd really like to know how common or rare it is...

there's only one consistent explanation for your reported observations. And this is the effect of a transient poltergeist and magic smoke. It could also be a side effect of having chrome-plated roll centers.

have you had other experiences of these either in the past or in the future ?

Hopefully you don't mind if I put out some wild ideas. All I've got is stabbing in the dark.

The best idea I have is that maybe a power supply capacitor was damaged and that the capacitor self-healed. I don't know much about how long that sort of thing takes (I just learned about it a moment ago), but say a filtering capacitor in the supply was damaged from high current somehow. Then the filter wouldn't work and high voltage transients were allowed to pass to sensitive electronics in the computer. Then high voltage transients on the mains, say from turning things on and off, then would put the processor into a bad state like latchup, corrupt ram, or stuff like that. But, over time the self-healing properties of the capacitor might have kicked in and then the filter would have started to work properly again.

Along those same lines, maybe a part failed in the computer, but it only caused noticeable problems as it was failing. So, when it worked well, it did it's job, and when the part was completely broken it didn't harm anything. Although, that doesn't seem to hold up with the idea that the problems you were seeing were precipitated by turning other things on and off. It's hard for me to imagine a sensitivity issue being caused by a marginally working part that wouldn't get worse when the part completely failed, but I suppose it's still possible.

Just some guesses. I had other ideas too, like if somebody else was somehow disconnecting or breaking the mains ground somehow or causing the power to be really dirty by plugging junk into the outlet. But, I'm not sure.

******* Edited
Okay, so I see the self-healing process takes somewhere around 10us while high current flows through the capacitor. So, that kills my idea. But, maybe (and this is even more far-fetched) the capacitor was being damaged each time there was an event on the mains from turning junk on/off. During the self-healing process, transients entered the computer and put it into a bad state. Since the capacitor was healed, it would happen the next time. Then, after this happened several times, the capacitor just stopped working or wasn't affected to high voltage spikes anymore.

kripacharya said:

there's only one consistent explanation for your reported observations. And this is the effect of a transient poltergeist and magic smoke. It could also be a side effect of having chrome-plated roll centers.

have you had other experiences of these either in the past or in the future ?

Click to expand...

Yes, I had some more similar experiences, there are some of them:

• We've got a battery shaver. Once it was in a drawer and when I was alone in the same room in the evening it suddenly began making a loud noise. At first I didn't know what was going on so I followed the noise. When I opened the drawer with the shaver it suddenly stopped. I wondered how it was turned on or off so I pushed the only one button on it. But it didn't react unless I pressed both sides of the shaver against each other. There is no any button on its sides and it didn't dent at all when I was pressing. But it reliably reacted to this and I turned it on or off cca 10 times over. When I told it at home the shaver wandered back to the shop for exchange so we don't have it anymore.
  
  
• It happened to me that warning lights of a car spontaneously turned on (i didn't push the button) when I was driving a car on a motorway. It was exactly at the moment when I was touching my navigation screen (on a cell phone) and not paying so much attention to driving. After that I swore a bit and my phone completely froze. There were a horizontal lines showing up on the frozen screen and covering the original picture.
  
  
• When my parents were on holiday and I stayed at home I noticed that our fridge had some problem. It had to stop to freeze a while before they left because when I took an ice cream from it another day it was already melted so it had to stop to freeze earlier to lose a cold. It didn't freeze exactly for whole time my parents were away. Everything in the freezer was totally melted. The day before they planned to return back the freezer began to freeze. It froze everything again during the night and when they came there was no problem about it.
  
  
• Our tv sometimes spontaneously change a numbers of tv stations. For example at first the tv station ČT1 has a number 15, then 17 and later 16...
  
  
• It often happens to me (in many dozens of cases so far) that street lamps goes off or on right above me when I'm walking or driving along. I don't know whether it's normal.. but I would say that normal is when the street lamp is shining in the dark (not repeatedly turning on and off).

The problem is that I don't believe in things like ghosts or paranormal activity (poltergeist). But maybe I'll have to change my opinion over time to explain this. It crossed my mind that the thing with pc (switching off monitors, freezing, speeding graphic card fan up to max) could be caused by somebody else controlling my pc remotely (a hacker.. because there were even other pc related coincidences) but that's probably only my paranoia.

How come that you think it's poltergeist, you have some experiences about it too?

beeflobill said:

Hopefully you don't mind if I put out some wild ideas. All I've got is stabbing in the dark.

The best idea I have is that maybe a power supply capacitor was damaged and that the capacitor self-healed....

Click to expand...

Thanks for your ideas, I appreciate it.

kripacharya said:

there's only one consistent explanation for your reported observations. And this is the effect of a transient poltergeist and magic smoke. It could also be a side effect of having chrome-plated roll centers.

have you had other experiences of these either in the past or in the future ?

Click to expand...

Hey kripacharya, could you please answer my question from the previous post? You always ignore me when I ask something... :-|

How come that you think it's poltergeist, you have some experiences about it too? And what do you think about other things that happened to me? Your answer will be appreciated!

Btw. the reason why I thought it could be a hacker is because the pc didn't react when I turned on the lamp when it was the light in the morning and with this exception only it reacted always (it wasn't happening randomly). As if somebody didn't expect that I turn on the lamp when it was the light in the morning.. But still it's probably only my paranoia.

I've heard of this kind of thing before, but never experienced it myself. A bit of googling brings up links like these:

https://en.wikipedia.org/wiki/Pauli_effect
**broken link removed**

godfreyl said:

I've heard of this kind of thing before, but never experienced it myself. A bit of googling brings up links like these:

https://en.wikipedia.org/wiki/Pauli_effect
**broken link removed**

Click to expand...

LoL :smile:

thanks godfrey... good reading !

I found an explanation for the thing with street lamps turning on or off:
"...street lights can turn off by chance, such as high pressure sodium street lights cycling (turning on and off repeatedly) at the end of their life cycle..." (https://en.wikipedia.org/wiki/Street_light_interference_phenomenon)

So it's usual to see this phenomenon. I'd wish I could find similarly clear explanation for the pc freezing thing..