Static electricity woes..

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roaf85

Static electricity woes..

Post by roaf85 » Thu Feb 26, 2004 2:15 pm

I just do not understand it! I mean I used to have a small mid tower crap aluminum case and it used to be even if I touched it with the slightest satic it would poof....and then my computer would not have power. Needless to say I was scared and somehow I was always able to start my computer back up and everything worked fine. So I managed to get a Antec Plusview 1000 and bam my troubles are gone. I am sometimes touched the side of my Antec case with static but nothing happens, unlike my old case. That is until last night, I was going to plug in my USB key and there is some metal around the usb connector and when I went to plug it in there was a shock and bam my comptuer turned off. I just do not understand. Is it just the metal? I mean no power connectors are touching the case. Can I be stanoffs? I used brass standoffs and used one washer to prevent the screw from coming in contact with the motherboard. I have never experienced this with any prebuilt, probably because they use plastic cases. I just do not understand.

bomba
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Post by bomba » Thu Feb 26, 2004 8:09 pm

You are experiencing electrostatic discharge oe ESD. A body (yours) charged with electrostatic energy comes in close proximity to a grounded surface (your PC case) and the electrical charge jumps the gap cuz it, like all electrical energy, just wants to get to earth ground. Note that ESD most definately can fry components, so you've been lucky so far. Best thing you can do is increase the humidity, which will greatly reduce the ability for electrostatic energy to accumulate; the moisture in the air acts as a bleeder cap. If this is not possible, discharge yourself onto another grounded surface before reaching for the PC. A metal light switch cover or the screws holding it down should do fine.

axhind
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Post by axhind » Thu Feb 26, 2004 11:59 pm

Is your pc grounded? I mean, is the plug of the pc connected to a grounded ... (I don't know the english word, but it's the thing in the wall where you plug in powercords :D) ? If it's not, your problem could be solved by grounding it.

silvervarg
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Post by silvervarg » Fri Feb 27, 2004 1:50 am

I agree with Axhind that this is defenatly a grounding problem.
I am fairly certain that you don't have your computer grounded.
Since you probably don't have any grounded wall plugs in the room you have your computer in your easiest way to reach ground is a heater.
Find some bare metal on the heater or the pipes to/from the heater.
Connect a cable from the heater or pipe to the chassi of your computer.

In case you have a carpet and like to drag your feet on it you will get lots of static electricity charge in your body, so to be really safe touch the heater before you touch the computer to discharge yourself.

If problems still persist after this easy fix you must have something in the computer that touches the chassi and shouldn't do that.

axhind
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Post by axhind » Fri Feb 27, 2004 3:24 am

silvervarg wrote:I agree with Axhind that this is defenatly a grounding problem.
I am fairly certain that you don't have your computer grounded.
Since you probably don't have any grounded wall plugs in the room you have your computer in your easiest way to reach ground is a heater.
Find some bare metal on the heater or the pipes to/from the heater.
Connect a cable from the heater or pipe to the chassi of your computer.

In case you have a carpet and like to drag your feet on it you will get lots of static electricity charge in your body, so to be really safe touch the heater before you touch the computer to discharge yourself.

If problems still persist after this easy fix you must have something in the computer that touches the chassi and shouldn't do that.
you have to be carefull when grounding your pc with a heater... they are not always grounded anymore. plastic connections and isolation can prevent the heater from being grounded, though they were in the past because every connection was made in copper or other conductive material. but you can always try this, chances are it will work nevertheless

BarCodeBlack
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Post by BarCodeBlack » Fri Feb 27, 2004 5:21 am

I'll have to admit, I have experienced this same problem, though, not to the extent of making my computers switch off. :shock:

Our house that we moved into last year is an old Spanish farmhouse, which fortunately has electricity points but non were grounded. Everytime I went to make some adjustments to any of my computers that were plugged in, I received a strange tingling sensation that was unbearable. We've since had adjustments done to the closest wallsockets to the computers, and the problem has gone away. It's far too much work to have all of the wallsockets grounded which, in all honesty, has me a little worried.

Problem now is, moving to a warmer climate like Spain has it advantages, but the air is much dryer and I just seem to attract so much static on myself, which is apparent when I get out of car and touch the metal bodywork, or even worse, meet new people, shake hands (or kiss the ladies on the cheeks, as is the done thing here!) and discharge all the static on them.! :oops:

Remedy: Not sure there really is one, I just make sure that before doing any work on the computers, removing any item from anti-static bags and such that I walk over to the closest machine which is plugged in and touch the rear of the case. I get some strange looks from the girlfriend when she sees me doing it from time to time, but at least it saves me a fortune in delivery costs when an item needs to be RMA'd.

bomba
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Post by bomba » Fri Feb 27, 2004 7:31 am

After reading thru the responses, I agree that it sounds like a non-grounded PC. In an electronic lab I used to do work in we had a piece of electronic test equipment that we intentionally operated un-grounded (to eliminate 60Hz ground loop noise). This equipment would generate about 30Vac on the metal case when measured with respect to earth ground and would give you a nasty shock if you touched it with one hand with your other hand touching a grounded piece of equipment or furniture. The rule of thumb and also an electricians rule of thumb to help avoid electric shock when working with possible live electrical conductors is to keep one hand behind your back.

Do what you need to to get the PC grounded. Ensure that your electrical outlets are 3-wire grounded. Buy a cheap multimeter and/or AC test light. If your electrical outlet appear to be 3-wire grounded, make measurment to be sure. For 115 or 230Vac single phase power, you should measure 115 or 230Vac from Line to Neutral and also from Line to ground. If you cannot measure voltage between ground and either of the other conductors, I suggest you call in an electrician to sort out your facility wiring.

silvervarg
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Post by silvervarg » Fri Feb 27, 2004 8:11 am

you have to be carefull when grounding your pc with a heater... they are not always grounded anymore. plastic connections and isolation can prevent the heater from being grounded, though they were in the past because every connection was made in copper or other conductive material. but you can always try this, chances are it will work nevertheless
Ture, it might not be a perfect ground-point, but it will be easilly accessible.
If the pipes are not electically connected the water will act as (a rather poor) conductor. It will at least be good enough to draw away the static from the computer chassi.
If it won't work to drain your own static electicity the trick with kissing ladies on the cheeks seems like a good trick :-)

trodas
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Post by trodas » Sat Feb 28, 2004 1:44 am

One thing is lack of grounding, and another is - why you get so much static :roll: My suggestion is wearing a different clotches too, 100% cotton ones help you to get rid of static you generating.
It could be just your chair and your sweater to cause the static - because grounding fix the results of your static, however only for computer and i will also look for preventing this from happening on the first place.

Shocking girlies with some electricity is not bad anyway :twisted: :twisted: :twisted:

Jan Kivar
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Post by Jan Kivar » Sat Feb 28, 2004 5:02 am

silvervarg wrote:
you have to be carefull when grounding your pc with a heater... they are not always grounded anymore. plastic connections and isolation can prevent the heater from being grounded, though they were in the past because every connection was made in copper or other conductive material. but you can always try this, chances are it will work nevertheless
Ture, it might not be a perfect ground-point, but it will be easilly accessible.
If the pipes are not electically connected the water will act as (a rather poor) conductor. It will at least be good enough to draw away the static from the computer chassi.
If it won't work to drain your own static electicity the trick with kissing ladies on the cheeks seems like a good trick :-)
Grounding to the heater isn't really a good idea. Think if your PSU malfunctions, making the entire chassis float in 60V/115V. If the heater system isn't properly grounded, it will also have 60V/115V. Imagine if someone then touches a heater in some other place in the house, while touching something that is grounded properly... :twisted:

Cheers,

Jan

roaf85

Post by roaf85 » Sat Feb 28, 2004 10:17 am

My PC is a 3 prong plug connected to a surge protector which is a 3 prong into a 3 prong wall outlet. I have no idea if the outlets themselves are grounded but this happened with my last case all the time at my old house and even at this house. I thought moving to this case would solve the problem I do not understand why it shuts off the computer? Is something wrong with my computer? I mean I know nothing is touching the case internally.

bomba
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Post by bomba » Sat Feb 28, 2004 4:50 pm

Perhaps your outlet or surge protector is not wired properly or is faulty, see my post above for troubleshooting

Gooserider
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Post by Gooserider » Sun Mar 07, 2004 8:59 pm

In the US at least, there are very low cost 'test plugs' that one can use to test outlets for proper grounding. You should be able to get one at any hardware store that sells electrical equipment, and the cost should be under $5.00 US.

It will look like an adapter plug with three LED's on it, when you plug the thing in, certain LED's will light up, and which ones will tell you the status of the circuit and if it's properly grounded. (The fancy ones might also have a push button to use in testing a GFCI circuit)

I would think that other electrical systems would have similiar testers since the concept is pretty simple.

I would strongly reccomend using one of these testers on each outlet, and if you get anything other than 'Good' for a result, either fixing it if you know electrics, or getting an electrician to do it if you don't.

If you are plugging into an outlet strip or a surge suppressor, I would also use the tester on the outlet strip to make sure it isn't defective.

Gooserider

silvervarg
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Post by silvervarg » Mon Mar 08, 2004 8:12 am

Jan Kivar:
Grounding to the heater isn't really a good idea. Think if your PSU malfunctions, making the entire chassis float in 60V/115V. If the heater system isn't properly grounded, it will also have 60V/115V. Imagine if someone then touches a heater in some other place in the house, while touching something that is grounded properly...
Well, imagine that you don't connect it to ground at all and the same problem happens. Then you will have 60V/115V on the entire chassi, and someone will sooner or later touch the chassi, so you got the same bad scenario except now you got perfect contact from chassi to person and no other route for electricity to go.
So, even if it is not a perfect solution, it is better than you had before and at least something possible to do with little means.
Proper grounding would be better, but usually not practically possible without heaps of work.

As the last posts have reveald it does not seem to be the problem that roaf85 has. He should have proper grounding all the way by the looks of his cables and outlets.
Since he still experiences problem some component must be faulty. I would start by checking the wall outlet, preferably with the kind of plug that was suggested. Cables can easilly be tested with an ohm meter (when they are disconnected), but I strongly doubt that they are the problem.

If everything else checks out, the fault is likely in the PSU. Either a loose cable or something more problematic. Before opening the PSU up read up a bit in the PSU forum section. Lots of good stuff and warnings there.
Don't take the warnings too seriously. Since you have been zapped a few times already and survived...

trodas
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Post by trodas » Mon Mar 08, 2004 8:15 am

I agree with Gooserider - proper grounding of the outlet, your PSU and case if the basic, where to start :wink:

I remember a little story about static electricity and C-MOS erasing that i have to write down there...

Even im electrician and have done all the grounding right, i get once to a problem with my invention. It's very simple - a small switch mounted on the pins what keep or reset the bios settings. Reasons for this are simple - my Abit AT6R oldie mobo lock for good everytime i try setting clocks to other that 1:3:3 - like 1:4:4 or 1:4:3 ... So with some experiments i learned that having a switch (no keyboard shortcut for erasing :? ) is wise and save me a lot's of time.
So i made it and let the switch on cable fall from the cumputer bottom (tehre are holes for better airflow made) to my desk. My computer are on layers of fake gras material (no idea of this is the proper naming, but one SPCR person used it, so maybe...) so i can reach bellow there easily and it's hidden - so perfect work, one could say.

The problem is, that my desk is from not fully wood material and the desk can - seems - catch some static electricity. As result, i getting occasional bios erasing - witch show me, that i have to unplug my invention and forget about it :?

...at least untill i got to replace the entiere disk with true wood and not something fake :?

bomba
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Post by bomba » Mon Mar 08, 2004 8:42 am

trodas,
If the 3rd wire safety ground to the PC is indeed not properly grounded, this is not a static (ESD) problem. Internal capacitors bridging high voltages and safety ground are left floating. This will allow the metal case of the PC to float with a certain voltage wrt ground. I've seen 60Vac on a electr. lab sine wave generator. Besides the PC reseting when touched, there is a legitimate safety hazard.

Phill77
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Post by Phill77 » Mon Mar 08, 2004 11:09 am

I'll admit not reading the thread fully, so forgive me if I have missed something.

Surely the PC must be properly grounded, else the static charge on the user wouldn't be discharging quite so readily?

I haven't been able to prove it yet, but often when I touch the case of my hi-fi, I get a static discharge and it locks up my usb soundcard which it is connected to.

bomba
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Post by bomba » Mon Mar 08, 2004 1:51 pm

Phill77 wrote:I'll admit not reading the thread fully, so forgive me if I have missed something.

Surely the PC must be properly grounded, else the static charge on the user wouldn't be discharging quite so readily?

I haven't been able to prove it yet, but often when I touch the case of my hi-fi, I get a static discharge and it locks up my usb soundcard which it is connected to.
Absolutely correct, electrostatic energy is loking for a path to ground so as you reach to plug in the USB cable, the electrostatic energy jumps the gap from the charged cable to the grounded surface, creating ESD. If roaf85 is experiencing an ESD problem, his PC most likely is grounded properly. To prevent ESD from resetting or possibly damaging the PC, he sould ensure that he is at the same (ground) electrical potential as the PC before connecting that cable, i.e. touch (discharge to) a convenient grounded surface other than the PC first. Note that raising the level of humidity in the room will dramatically reduce the occurance and severity of ESD events (the humidity acts as a bleeder cap. to ground).

If, however, the PC (or any Class 1 AC powered product with 3-wire grounding power cord) is not properly grounded; a user touching the PC may receive an electrical shock. I'm sure we all know what it feels like when we reach for the light switch and experience an ESD event from our outstretched finger to the light switch. Hopefully, there are much fewer of us that have been shocked; but for those that have, the difference is clear.

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