static - dangerous?

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metallicafan

[H]ard|DCer of the Month - May 2010
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I have read and have been told that when working on computers static electricity is a danger to the individual components. Some suggest that using anti static mats and wrist bands are a good practice. However I see many techs replace components with out these anti static devices. How big of a problem is this and should i be using ESD devices such as wrist bands or mats ? thanks
 
How long have you been doing this?

Not an insult just a question. It is very common knowledge and important knowledge... yes yes yes, static can mean the life or death of a PC part... like building your PC sitting on your carpet with a pair of socks on fresh out of the dryer..... no no no no....
 
antistatic wrist bands, for most computer technicians are a mere annoyance.

Generally, as long as you play with the metal of the case around the components before digging in, its good enough.

But if you don't feel comfortable about it, then go with a antistatic mat/wrist band...

I personally have been building computers for 6-7 years, and worked as a technician at Circuit City for a stint and have yet to electro-shock something.

Knock on wood, so you never know.
 
depends where you live to, in south carolina, we dont get much dry heat, so its ok, out in dryer places its best to have a grounded strap in case........i never use it, but i make sure to ground myself (holding psu and rubbing it a bit) and havent done anything bad yet *knock on wood*


soulsaver_8229
 
Murali said:
Generally, as long as you play with the metal of the case around the components before digging in, its good enough.
Click to expand...

Yep, always touch something metal like a lamp or the case before working on the machine. It doesn't take more then a second and is "good enough" in my experience.
 
Static won't be a problem, just as long as you touch a metal object (any metal object, if you have enough built up static you'll feel it leave your body, trust me...), and assemble it in an anti-static environment, like a wooden desk, or on an anti-static bag, just to give a couple of examples.

Wrist straps are just plain anoying, and generally if you touch a metal object before touching the parts, you make the strap redundant. And obviously ground yourself every now and then to make sure that you get rid of all the staic you may have accumulated.

I've never had a problem with static damaging components, just follow those ideas and you'll be right.
 
I have to agree with most of the above... If you touch the chassis before fooling around, you should be fine. Today's components are a lot less sensitive to ESD than those of say 8+ years ago. But.. As stated above, don't go messing around inside of your pc wearing wool socks on shag carpet :p
 
dlion said:
I have to agree with most of the above... If you touch the chassis before fooling around, you should be fine. Today's components are a lot less sensitive to ESD than those of say 8+ years ago. But.. As stated above, don't go messing around inside of your pc wearing wool socks on shag carpet :p
Click to expand...
i worry about the carpet in my room... i feel like a total nerd saying this, but i work on my computer in my boxers so as to avoid ESD. everytime i shift my weight i try to re-ground myself on the chassis.

i've fried a sound card before with static... thank god it didn't destroy anything else in my machine at the time!
 
Zinn said:
i worry about the carpet in my room... i feel like a total nerd saying this, but i work on my computer in my boxers so as to avoid ESD. everytime i shift my weight i try to re-ground myself on the chassis.

i've fried a sound card before with static... thank god it didn't destroy anything else in my machine at the time!
Click to expand...



rh

relative humidity

a teaser from the link Papa-Ming provided
Table 2
Examples of Static Generation
Typical Voltage Levels

Means of Generation .........10-25% RH ......65-90% RH
Walking across carpet ......,35,000V ...........1,500V
Walking across vinyl tile ....12,000V ............250V
Worker at bench ................6,000V .............100V
Chair with urethane foam ..18,000V ...........1,500V
Click to expand...
the humidity level plays a major factor in how serious and event can be
and alot of techs work at grounded workbenches, but then alot of them are cavalier about ESD precautions as well, the latent defect isnt going to be attributed to them and just might bring more work in the door :rolleyes:


& the full ESD & Electromigration Rant
 
so humidity is good, excpet when its frickin hot too and you have to wipe off your forehead every two seconds cuz you dont want sweat dripping onto your mobo. That towel was soaked before I was done putting my comp together
 
thanks guys. . . ive always heard about ESD being a problem but i wasnt sure how much truth there was in that. I usually keep a spare case/power supply pluged in near me when i am building computers and I ground myself on the grounded PS now and then. Looks like that is what many people do. thanks again
 
Table 2
Examples of Static Generation
Typical Voltage Levels

Means of Generation .........10-25% RH ......65-90% RH
Walking across carpet ......,35,000V ...........1,500V
Walking across vinyl tile ....12,000V ............250V
Worker at bench ................6,000V .............100V
Chair with urethane foam ..18,000V ...........1,500V
Click to expand...
Hmmm, using those stats, I now know why I get hurt bad every time I get a new PC out of its box, with plastic bag and styrofoam packaging. With the low RH I experience in the winter we are having down here, I would estimate, using the bolded figures and making a few assumptions, that I get hit with over 25,000V after unpacking one of those cases. I know I have to touch it before working on it, but it always hurts so much. Last week I zapped myself real bad, my whole arm was pushed backwards and I had spasms in my arm for a minute afterwards.

I couldn't imagine what that would do to a motherboard, unleashing 25,000+ volts at it for a long split second. Ouch.
 
Yea someone just meantioned it, but heads up to all the ESD newbies. Touching the metal does nothing if it's not grounded. The best thing is to have your PSU plugged in, but flip the switch in the back so its off. Even though it's off, it's still grounded, as is the case if the PSU is installed.
 
and be aware that if the PSU doesnt have a switch to turn it off
unlike AT supplies there is a constant powering of the mobo with ATX supplies for Wake On LAN, WAN ect so....

ESD Precautions and Practices
The ATX motherboard specification maintains +5VSB power to the motherboard
unlike PC/XT, AT, Baby AT and LPX form factors that employed a manual switch to turn on the power to the motherboard, the ATX form factor employs a "soft power" scheme
allowing software control of power, allowing the OS or other ap to turn the computer off, it also allows wake on LAN or Wake on WAN. Since there is a low level of power supplied to the board at all times, you need to address this whenever your swapping out components

the ideal solution is to unplug the power supply from the socket then ground the case with an alligator clip to a seperate ground point and use a wristrap to ground you

the alternative method is to turn off the PSU with its own switch
reliable only if the board has a 5VSB LED indicator on it
at which point you know the board is unpowered, yet the case is still grounded via the AC Socket

the alternative method if there is no switch on the PSU and LED mobo power indicator is to unplug the PSU from the wall socket, then disconnect the main power connector and plug the PSU back into the AC Socket, where once again you have the case grounded

keep in mind that typically the PSU physically contacts the case with a metal to metal contact, at least in the past, and would have at least some contact via the screws, but these adys with painted cases and supplies, some augment that with a grounding strap for the PSU itself (very typical in server supplies where they take no chances with contact)

and religously touch a bare metal surface in the case to ground yourself when swapping componets (this is very typical in here with enthusiasts)
but all in all wristraps are cheap and so are alligator clips and a bit o wire
a grounded work pad is also a good investment, as is being aware of how large a role the lack of humidity has in ESD events, especially in Winter when hot air heating desiccates the moisture out of the air

(see I live on the Rocky Mountain High Dessert Plateau, where its already dry and in Winter with central home heating I humidify the environment when working on components)
Click to expand...

a point especially important when swapping out memory
memory is likely your most suceptible ESD victim, as its mostly leads and IC chips :p
 
n64man120 said:
Yea someone just meantioned it, but heads up to all the ESD newbies. Touching the metal does nothing if it's not grounded. The best thing is to have your PSU plugged in, but flip the switch in the back so its off. Even though it's off, it's still grounded, as is the case if the PSU is installed.
Click to expand...
...yes and no. What touching an ungrounded case does is to equalize the potentials between you and the hardware. It matters not if you and the case are both charged to 10KV+ if you are both at the same potential, as there won't be a discharge event as the charges try to equalize when you touch something.

I still do this, even when I'm working on my grounded work surface. The key is to equalize the potential of you and the hardware, I think.

FWIW - B.B.S.
 
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