VOGONS


Is the risk from static damage overblown?

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Reply 20 of 24, by jaZz_KCS

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badmojo wrote:
derSammler wrote:

Very true. Touch the SID chip of a C64 without ESD protection and you'll fry it with a 99% chance.

I’ve done a lot of handling SIDs without ESD protection and live in a very static prone environment - never had one die on me. Pretty sure you’re just making shit up - wouldn’t be the first time.

A little peeved, are we?

Reply 21 of 24, by wiretap

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dionb wrote:

Would love to have those kind of resources 😀

It is expensive as hell. Each test/report is usually over $20k. 😲 Keep in mind though, we do this because it is for nuclear Q1 safety related components only, so you have to 100% for sure know a failure mode to see if it is a common mode failure that could affect other components that are in-service for an operating nuclear reactor control system or safety system. Sometimes we find a manufacturing defect, and if it applies to more than one component, we file a 10 CFR 50 Appendix B (https://www.nrc.gov/reading-rm/doc-collection … rt050-appb.html) notification and black-list the component so other nuclear plants can replace the components with the known failure mode before it manifests itself. (and so the manufacturer can recall it / fix it in a future revision)

My Github
Circuit Board Repair Manuals

Reply 22 of 24, by maxtherabbit

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I always touch a grounded object before handling components, I also don't wear socks on carpet like a weirdo. My boots don't seem to collect charge from walking around. My theory is that most of people's static problems come from inferior clothing and shoes

Wearing a god damn bracelet is just a bridge too far, not doing it no matter the cost

Reply 23 of 24, by retardware

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Just to add to @wiretap's excellent writing, I would like to emphasize again that believing that "grounding" is a safe ESD precaution is a potentially disastrous misconception.

My most recent component damage didn't result from static discharge, it resulted from the grounding of a (supposedly) potential-free circuit connected to an insulated power supply. However, there was a *very* small capacitance between mains and output, causing mains voltage hitting and shorting two adjacent output pins of a CMOS IC that happened to touch "ground". The malfunction resulted in a newly created OR gate - if one pin got high, the other one went high also.
The cause wasn't ESD in this case, but the effect was basically the same.

Again, the only proper way is to make sure that your potential is the same as the circuit you are handling.
As I am a lazy retarded dog, I do not like chaining myself using wrist straps.
I just make sure I am always the same potential by, for example having always one arm lying on/touching blank metal parts of the computer case I am working on.
The same when I work with stuff on ESD mats.
The only thing I permanently chain to "ground" (or better called "common potential") is the soldering iron, which is connected to the ESD mat via clamp.

I'd be careful about using the electric grids' "ground"... it is often not recommendable, especially if it is a high resistance grounding.
Or even worse, particularly in the cases where there are still two-wire circuits with the wall outlets' "ground" connected with the neutral wire.
As in my home the electric installation is of the latter kind, I absolutely prefer to disconnect all direct and indirect connections to grid "ground" of valuable hardware like old computers, before I work on their innards.

Thanks again to @wiretap, @dionb, @jo22 and the others who try to inform people about the catastrophically underestimated ESD risks!

Reply 24 of 24, by PCBONEZ

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.
Nailed it right here.

dionb wrote:

....the damage is cumulative. Decades of unsafe handling will lead to more failures than a short period.....

You usually won't see the damage immediately but that doesn't mean it hasn't been damaged.
.
It's like bending a wire back and forth until it finally breaks.
Each time you handle something improperly you've bent the wire again.
.

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