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Reply 20 of 30, by Jo22

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This thread reminds me of an Apple II service video..
https://www.youtube.com/watch?v=2WNb3TUNf0A

"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel

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Reply 21 of 30, by Tetrium

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20:35 reminds me of something both that tech guy and myself can relate to 🤣

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Reply 22 of 30, by computergeek92

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Tetrium wrote:

20:35 reminds me of something both that tech guy and myself can relate to 🤣

Seems it's correct that the early PCs were more vulnerable to ESD except for 386 and 486 and a bit later like the Pentium.

In practice, I put the tower on an antistatic mat and use a wrist strap. Both the mat and the strap are clipped to the fins of a large metal heatsink placed on the mat. I do what they say in the video except for plugging the pc power supply to the the wall socket. That's because I’ve heard you don't want any current running through the PSU, that can be dangerous.

Though if the plugged in PSU method actually is the best option I suppose you could leave it plugged in but place the PSU unit on the mat and clip the mat and wrist strap to the PSU...

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Reply 23 of 30, by Kodai

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You want the PSU screwed into the case. There is a common ground lead or connection made from the PCB of the PSU to its case. That ground is in part connected to the case when the body of the PSU is connected to the case via the screws. When a static discharge occurs from touching the case, it will then travel through the case, to the PSU, and out the third prong of the IEC plug.

Some of the better cases will go the extra route and sand down an area of the case (if it's painted inside) and attach a heavy gauge "green" wire to be screwed to the PSU to insure the best ground. I haven't seen that in a good 5+ years, but it wasn't that uncommon back in the day.

My U2-UFO case is like this, but it's 6 years old now. I always work on all my PC's by starting with either plugging in the PSU first (for out of case testing), or mounting and plugging in the PSU. That's the majority of my esd guarding. Funny thing is I got into the habit in the '80s from an apple ii third party service manual. The thing was bigger than a super sized phone book. Kinda wish I still had it.

Reply 24 of 30, by shamino

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I'm pretty sloppy about this stuff usually. I'm more careful if I'm handling something that I consider valuable and prone to fail, like say an ISA sound card. With most common components I don't think much about it, but if I notice I've been shuffling my feet on the floor or anything I'll occasionally touch a grounded PC case (there's always one handy, 🤣).
I don't know of any example where I damaged anything with ESD, but then it's hard to verify so who can ever know. I believe it can happen rarely. Usually though I think it tends to just be a convenient scapegoat in situations where people don't know why something doesn't work.
Some level of ESD protection is generally built in with ICs, so in the absence of any such protection I don't know how much more common this problem would be.

computergeek92 wrote:

In practice, I put the tower on an antistatic mat and use a wrist strap. Both the mat and the strap are clipped to the fins of a large metal heatsink placed on the mat. I do what they say in the video except for plugging the pc power supply to the the wall socket. That's because I’ve heard you don't want any current running through the PSU, that can be dangerous.

That depends if the power supply has any standby power or not. AT and most other old power supplies (like in an Apple II) are mechanically 100% switched off and have no way of turning themselves on. With a PSU like that It's better to leave it plugged in because it provides grounding. The rule changed with ATX because those have standby voltage rails that are always active when the unit is plugged in so it's safer (for the equipment) to unplug them while working. Unfortunately that leaves the chassis without an earth ground though.
Come to think of it, some ATX PSUs have a switch at the back to cut their power 100%, so with those I guess they should be treated like AT supplies - leave them plugged in and just disable the switch at the back. I'd always be afraid of making a mistake though so I'm in the habit of unplugging them, even if it's not the "right" way to do it with regard to ESD.

Reply 25 of 30, by DosFreak

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As a member of the military we have to take ESD training and we are taught that ESD is cumulative.....and we all know how finnicky electronics can be. It's can be hard to determine if an issue was caused by ESD by the user handling the equipment improperly, power surge, came that way from the manufacturer etc etc. Always be grounded. Works for electronics just as well as everything else.

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Reply 26 of 30, by Kodai

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Most modern PC hardware is built with large ground planes and a few and resistors and diodes that will handle the average jolt from ESD. That's why you really don't hear about it nowadays. Back in the 80's, and 90's it was constantly talked about. Other than being a little cautious about how you handle a CPU or stick of RAM, pretty much everything else should be able to handle a brief moment of a few thousand volts. It really isn't something to go out of your way to deal with on modern rigs.

I'm not suggesting anybody throw on wool socks, dance a jig on shag rug carpet in a dry room and start touching your motherboard or video card. Just pointing out that wrist straps and esd mats are kinda overkill for building modern rigs.

I do use them, but only when I'm at my electronics workbench and building, modding, or repairing some gadget or old computer/console. Infact I have a home made heavy ground station made from six, half inch copper rods, that are six feet long and buried almost six feet into the ground, six inches apart. I connect to it for my crystal radio projects as well as electronics work. When not in use I have a knife switch connected inline with a lawnmower sparkplug. It's setup to help ground near strikes during electric storms in my workshop.

I even check my soldering stations for correct grounding every six months. I use a couple Hakko 951's, an FP 102, FM 202, and a pace desoldering station. I also use esd safe edsyn solderpult's for when I don't need to break out the desoldering station. Even my alcohol pump bottle is esd safe as are my flux bottles. So I'm not adverse to playing it safe. I just don't bother with it on new hardware as it really is more trouble than it's worth.

Last edited by Kodai on 2016-12-05, 12:35. Edited 1 time in total.

Reply 27 of 30, by Jo22

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Yes and RAM chips always have been very sensitive. Like for example old static RAM from the 70s/80s (SRAM). 😉
Other types, like ancient TTL ICs, weren't that sensible, though, as they were built in a more primitive way (larger structures).
And I assume recent CMOS designs also include some kind of internal ESD protection - to withstand novice users. 😁
Anyway, it's wise to equally handle them with care. Just recently I've got a broken LM386 IC (was part of a kit).. Perhaps it also got damaged by ESD ?

"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel

//My video channel//

Reply 28 of 30, by skitters

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If you come across an eBay auction where a motherboard is pictured on a towel or blanket or rug where you can't tell for sure if it's made of a cotton or a synthetic material, should you assume ESD damage?

For example these two ...
http://www.ebay.com/itm/152352267934
http://www.ebay.com/itm/162316667151

I have a polyester blanket that looks much like that blue thing he laid those motherboards on for the picture, and my blanket is almost always full of static.

Reply 29 of 30, by firage

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That carpet sure looks unnerving, but who knows. Just be prepared for thorough testing and taking advantage of the no DOA guarantee there. May not be worth it.

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Reply 30 of 30, by skitters

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firage wrote:

That carpet sure looks unnerving, but who knows. Just be prepared for thorough testing and taking advantage of the no DOA guarantee there. May not be worth it.

That's what I thought.
Apparently someone else thought differently though, because the Gigabyte GA5-AX is sold.
$79.99 is a good deal for that model if the motherboard is good, but I don't have time for exhaustive testing right now.