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Do you use an antistatic wrist strap when working on hardware?

Do they really work?

Have you ever fried some hardware that would have been saved if you had been wearing one?

I know some people who wear them religiously and others who say they are a waste of time.

What is the view of the community?

Charles Roper
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    Remember, "the view of the community" isn't really relevant if it doesn't agree with the actual physics.... – Bob Cross May 15 '09 at 20:38
  • The view of the community means something if you're making a value judgement, though. A bit like asking, is RAID x worth it? Or, is browsing with Javascript disabled worth it? It depends on the situation, of course, but just because bad things *can* happen doesn't mean they *will* and so you have to weigh up risks vs. the precautions. – Charles Roper May 19 '09 at 09:05

13 Answers13

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Here's where experience may lead you astray. Static discharges can create partial burn-throughs in those nanometer lines inside a chip. So the part may not fail immediately. But it can certainly cause premature failure down the line. So if your experience tells you that you've never "fried" any parts while working on them - what you don't know is how many will prematurely fail in the future. I always use the straps in a professional environment, but for low value home stuff I generally just ground myself.

Knox
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    +1,000 - Young engineers need to know that static damage can and will occur that may not be immediately noticed, and the static discharge required to damage an IC is less than the static charge that you can see, feel, or hear when it occurs. Just because you don't sense static doesn't mean you aren't damaging your components. It's not worth the time spent troubleshooting the problem - the video card works _most_ of the time, and so you spend hours installing software, drivers, trying to see if there's a conflict with another resource, etc. It's not worth it. – Adam Davis May 15 '09 at 18:53
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    +1 You will never know when you've damaged a chip... – Oskar Duveborn May 15 '09 at 21:05
  • Are there any studies or other scientific evidence to back this up? I'm not refuting the claim, just interested in the evidence. It would be interesting to run a long-term study with 3 groups: a wriststrap group, a non-wristband but taking other precautions group, and a control group who know nothing of the experiment. Then compare the hardware failure rates of the groups. – Charles Roper May 19 '09 at 08:57
  • It would be interesting to see the outcome of such a study. When I worked at a large electronics company as an electrical engineer, one customer had very rigorous quality requirements, so every failure was analyzed by development engineers to find the root cause. Especially as Adam Davis indicated above, some static damage can occur without humans being aware. Static damage was seen by the team under the microscope when analyzing failures. – Knox May 19 '09 at 10:47
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    Charles and Knox, please go to http://www.esda.org/esd_fundamentals.html It's an industry standard backed up by millions of dollars of inspections of failed parts. – Tim Williscroft Nov 20 '09 at 00:15
  • @Tim Williscroft, very good reference, thanks. +1 – Knox Nov 20 '09 at 16:18
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I've never worn one and never fried anything that I'm aware of.

I always make sure I touch the power supply and ground myself (relative to the computer) prior to touching any of the static sensitive components.

If I were working in a very staticky environment- lots of rugs, cold dry air, etc, I'd potentially reconsider (or ground my bench), but I'd probably avoid that kind of location for my workspace anyway.

Tim Howland
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I can't say whether or not they have saved any hardware I've been working on, but I have a suspicion they did me some good when (in my trainee days) I managed to electrocute myself on an old AT power supply. I think the antistatic band provided a good earth for the charge rather than it crossing my chest. So, if your a young idiot who unplugs the wrong power supply, you should definitely wear one!

Sam Cogan
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  • Do you use an antistatic wrist strap when working on hardware?

Yes.

  • Do they really work?

Yes.

  • Have you ever fried some hardware that would have been saved if you had been wearing one?

Yes. Once, a long time ago. That "proved" the issue to me very quickly in a very painful fashion.

  • I know some people who wear them religiously and others who say they are a waste of time.

If you don't care about the dollar amount of the hardware you're attempting to protect, then yes, it's a waste of time.

Frying an $800 high-end RAID controller card because someone didn't take anti-static precautions, well...let's just say that was a bad choice.

I now wear one whenever I work on equipment.

It takes only a few hundred volts to fry a circuit. To feel a static discharge, you need to have thousands of volts. In other words, you can kill chips easily without knowing it.

Avery Payne
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When working on my own hardware, I never bother to wear one, nor have I ever had an issue. But when I am at work and I am toying around in enterprise class servers and storage that cost upwards of $00k, I generally wear one.

In fact, many replacement parts I receive now (namely from Network Appliance), include a crappy disposable static strap. When they do that, it shows you that not only do they value the use of one, but also gives you no excuse not to use it.

I would say, it would be in your best interest to use one when working on someone else's hardware, but use your own discretion when working on your own.

WerkkreW
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  • The problems with "I've never had a problem" is that many of the static-caused problems are hard to detect, intermittent and infuriating. Basically, this is classic confirmation bias: "Look, I got away with it again. Those things must be bogus!" – Bob Cross May 15 '09 at 19:47
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I personally don't wear them, but just make sure I ground myself prior. I've never fried any hardware from static (shock, completely different story...). HOWEVER, I have seen MANY microcontrollers toasted in our electronics lab. If you enter that lab without an anti-static strap on you get written up.

squillman
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Grounding yourself on the power supply works, but only if the power supply is still plugged in! A wrist strap is good, if it is properly connected to ground. Also this is not a dead short, but instead is a high resistance path to gradually dissipate any existing charge and to keep any new charge from building up. I like the kind that come with a plug to connect to an outlet. They have an LED that verifies the outlet ground is OK, a clip to attach to the computer case, and a wrist strap. People are correct to point out that ESD is not a single bright spark that kills a chip, but is gradual damage that shortens the life of a component.

Jim C
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I have a PC sitting next to me that locks up under heavy disk IO. It started doing that after I installed a network card. So yes, I have "fried" hardware that would have been saved with a strap.

pgs
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IMHO, it's better to prevent static buildup in the first place. If you wear cotton clothes, then you shouldn't have any buildup at all.

vartec
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I don't know for sure if grounding your wrist is adequate protection. But, I can say I've fried an MFM hard drive controller with my curiosity. Touching parts of the board while it was on made the drive light flicker... until it flickered no more.

Generally, I handle all electronics with respect. Before touching anything sensitive, I touch a grounded surface first, like the chassis. I only hold boards, memory sticks, etc. by the outer edges to avoid touching metal contacts. I avoid being near anything that is statically charged, like certain types of furniture, blankets, etc.

spoulson
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I've been lucky; the only hardware I've ever fried was when I spilled a drink on the keyboard and the keyboard controller chip on the motherboard burned out. My attitude toward anti-static straps is smoke 'em if you got 'em.

chaos
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If you stay well clear of clothes that build up static (like fleece), and you are careful it should be OK. I do it all the time at home, but when I work on a server or something that really matters I ALWAYS use a wristband connected to the chassi.

If I'm just popping in a few RAM sticks at home, I just make sure to touch and hold the metal chassi when doing the work, that way I'm grounded through the PC.

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I have worked for a large hardware company (as a programmer) at which all new employees had to take an ESD tutorial and pass a quiz in their first couple of days before starting on real work. Despite all this caution and the warnings posted about the dangers of static, I don't think I ever saw anyone wearing the bands or using anti-ESD mats or anything.

Even when working on my own machines at home, I just touch the chassis before working on anything, and I've never destroyed any hardware. Of course, you should use common sense and pay attention to what you touch, but for the most part, fears concerning ESD tend to be blown out of proportion.