How are PC components grounded?

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TomMe

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Since I learned about ESD, I'm trying to piece together how I should properly handle PC equipment. One thing that I know nothing about, is the "grounding" of PC components, and I think this might be important to know when handling them (especially with danger from ESD).

I would like to know how components inside a PC are grounded and if the PC case itself is connected to the same ground? Does it have anything to do with the metal standoffs that support the motherboard?
 
TomMe said:
Since I learned about ESD, I'm trying to piece together how I should properly handle PC equipment. One thing that I know nothing about, is the "grounding" of PC components, and I think this might be important to know when handling them (especially with danger from ESD).

I would like to know how components inside a PC are grounded and if the PC case itself is connected to the same ground? Does it have anything to do with the metal standoffs that support the motherboard?
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All components should be connected to a ground because then they wouldn't work (ground is really just a reference voltage) so yes.. all components have the same ground.. however that ground might be connect through smaller points to reduce noise in the electronics.. but they should all have the same ground for the most part

you really don't have to worry that much about ESD.. i don't know why there as been an explosion of ESD threads..

just build you computer and be happy.. the engineers took care of most of your ESD problems
 
and yes the case acts like a sort of ground as well as the ground wires in the power connectors.


ESD is really not that big of a worry though, just don't rub your feet accross the carpet and make a lightning bolt into your processor or mainboard or something and you should be fine :p
 
There are lots of posts about ESD because the winter air is dry and static electricity is rampant. You absolutely should worry about ESD as it can take out a piece of sensitive equipment easily. Easiest way to rid yourself of any static charge is to touch a metal part of your case prior to removing and handling something like a stick of RAM or vid card. Toucjing a metal part of your case will equalize the charge your body carries with the charge in all your components.

Normally the above is enough. If, however, you live in a very charged environment (you get shocked all the time) then wear an ESD wrist strap connected to the case. When transporting or storing anything like a RAM stick or HDD, place it in an ESD bag.

If your home is not charged then you can relax a bit but always be aware of static electricity when you have that stick of RAM in your hand.
 
How about using the 'real ground'? Prepare and assemble your case and components outside in the dirt ;) That is where the term get's it's name you know...

Really all this hoopla about 'ground' isn't technically about grounding. Esd could care less about grounding. The real problem is when 2 objects are at different electrical potentials. Like any other force, electricity wants to come to a balance and will attempt to migrate from greater potential to lessor.

Personally, I would look for another paranoia to obsess about. You are making way more of this esd thing than there is to worry about.
 
Who is being paranoid? WTF. I told the OP to touch a piece of metal on the side of his case to equalize charges and that is called paranoid? So take absouluetly no precautions against ESD while handling sensitive electronic gear. That is a great recommendation to make.

Use your heads guys when making recommendations to new builders. You have no idea how much static he has in the area he is building his rig. If you truly believe that ESD poses no hazard to sensitive electronics then please do some more research as you are woefully uninformed.
 
Merc said:
Who is being paranoid? WTF. I told the OP to touch a piece of metal on the side of his case to equalize charges and that is called paranoid? So take absouluetly no precautions against ESD while handling sensitive electronic gear. That is a great recommendation to make.

Use your heads guys when making recommendations to new builders. You have no idea how much static he has in the area he is building his rig. If you truly believe that ESD poses no hazard to sensitive electronics then please do some more research as you are woefully uninformed.
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well of course you should touch the case alittle bit.. but other than that... i wouldn't do anything else when it comes to ESD
 
Merc said:
Use your heads guys when making recommendations to new builders. You have no idea how much static he has in the area he is building his rig. If you truly believe that ESD poses no hazard to sensitive electronics then please do some more research as you are woefully uninformed.
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The point being, this series of posts, and the related ones in the sticky etc., are going far beyond the simple, common sense suggestions such as 'touch the pc case before you handle or install components', and into territory that imo only further serves to confuse the issue. My sarcasm exists here to 'ground' the topic back to that simple point, and avoid the esoteric hypothesis of current flow and pc cases on carpet...

The other threads pretty much covered the handling issues already, and this thread on 'grounding of PC components' is a topic ripe for heading off course into discussions that will hardly benefit the beginning builder, if not outright confuse him more. What aspects of a pc's electrical ground design help esd prevention for the beginner builder? Shall we throw rfi & emi into the mix as well? Ground loops?
 
agent420 said:
What aspects of a pc's electrical ground design help esd prevention for the beginner builder? Shall we throw rfi & emi into the mix as well? Ground loops?
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You're right--ESD and grounding are (almost) entirely separate issues. And if you've got ground loops inside your computer case, you've got bigger fish to fry. :p

As far as ESD is concerned, here's my suggestion: while working within your case, just make sure you touch some metal part of the case every once in a while. As someone else said, ESD is caused when your body is at a different voltage from the computer. Touching the case every so often will bring the two of you to the same voltage, and keep you safe.

As for grounds, everything in your case is grounded typically in two ways. The first is through all the black power wires which you see on every power connector. The second is through the actual case. Your CD-ROM drive, for example, has its metal casing connected to computer case, and the computer case is connected to the power supply, and the power supply has its case tied to ground.

 
Perhaps one of the reasons that there are so many ESD threads is that so few of the ones we have have correct, clear information.

The power supply's return line is certainly needed, and is referenced as a "ground". But it doesn't provide an earth ground appropriate for ESD. The input side ground, connected to a house ground, does provide adequate grounding for ESD -- coupled with appropriate ESD tools.

A PC power supply inside a case, connected to the outlet, grounds the case. This will adequately (but not perfectly, and not safely) dissipate static if the builder is careful.
 
pwnage101 said:
is it safe to just use rubber gloves when building a computer?
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Static charge does not require a conductive material. In fact, insulators are better at accumulating and storing a static charge than conductors. Rubber can actually be a great generator of static electricity. Some versions of Van de Graff generators use rubber belts to accumulate a charge. You are probably increasing your risk by using rubber gloves.

I'm not sure why there seems to be this great determination to circumvent the simple methods of touching the case or wearing a wrist strap.
 
If I'm working on someone else's box, I either use my wrist strap or heel strap, no big deal.

On my own box, I just leave it plugged into the wall with the PSU switch turned off, and just touch random metal parts ot the case every now and then.

Last thing I lost to ESD was a tiny microcontroller at work because my heel-strap was shot.
 
Me, too; I blew a little Atmel evaluation board.

But according to Rancid, we must be lying.
 
mikeblas said:
Me, too; I blew a little Atmel evaluation board.

But according to Rancid, we must be lying.
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Yeah, most PC-scale hardware (large, one-piece boards or hardware) are pretty damn resilient to ESD nowadays. (I have carried around a Radeon 9200 barefoot on carpet before and nothing died...sure, it wasn't a great idea, but its a 9200, so >.>). I still don't take as many precautions as possible, but at the very least working on a non-carpet surface (I use my chairmat or desk), and touching the PSU or chassis is the minimum that should be done. Leaving it plugged in (with the PSU power switch off) also supplies ground.

But yeah, microelectronics/embedded systems...can be very sensitive. :(
 
mikeblas said:
Me, too; I blew a little Atmel evaluation board.

But according to Rancid, we must be lying.
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i'm just syaing.. when a board mysteriously dies.. it doesn't mean it was ESD.. it could have been a problem that was progressivly getting worse due to poor design.. or manufacturing defect, or poor use of it in a system..

i handle TONS of electronics on a daily basis.. Everytime a board died on me.. i've always discovered that it was due to poor use of the component in my system...

that's all..you can't just point the finger at ESD.. there's no way to really prove it either...

i think small micro controllers are as resilient to ESD as any PC hardware out there.. when people design IO pads for small chips.. they beef them up pretty damn good..

i just think blaming failures on ESD is a cop out 9 out of 10 times...
 
I think the question being asked is - 'why don't signal & power cables cause ground loops'.

I'm pretty sure the answer is that,
There is 'earth' which is the metal case, hdd shell, etc.
There is '0v' which is the black cable coming from the power supply. this never looped & only connected together in the psu.
There is 'data gnd' which is isolated for each & every data connection.

None of these 3 will ever be connected (except via pull up resistors or such like).

:confused: Can't see it working if none of the above holds :rolleyes:
 
i'm not saying that you should not take precaution when handling parts... but i mean.. you don't need to be paranoid about it...
 
Wow.. :eek: I didn't really expect so many replies when I posted my message! Didn't expect it to turn into a pro contra ESD discussion either. :(

I wanted to know how components are grounded, because in the ESD FAQ someone mentioned that grounding a computer provides a safe path for current from an ESD to follow. And I also wonder why some people connect alligator clips to a computer case to ground the whole computer.

Further I'm just interested to know about grounding computers in general because sometimes I connect my computer to a non-grounded outlet out of necessity, and I'd like to know if this can cause damage to it (so to avoid it in the future). Or is grounding just for protection against electrocution?

I thought this might be a useful topic, so I created a separate thread about it.

mikeblas said:
Perhaps one of the reasons that there are so many ESD threads is that so few of the ones we have have correct, clear information.
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Exactly mikeblas. Perhaps some day someone will make a clear guide about ESD protection for PC hobbyists and users (with nice colour pictures :p ). Until then it's just scraping together pieces of the puzzle.

And yes, if something breakes it's not necessarily due to ESD..but why take the risk if you can minimize it by taking it into account when handling? At this point, I'm just going to reread all this stuff posted about ESD here before saying anything else. :)

Thanks for all the replies so far!
 
TomMe said:
And yes, if something breakes it's not necessarily due to ESD..but why take the risk if you can minimize it by taking it into account when handling? At this point, I'm just going to reread all this stuff posted about ESD here before saying anything else. :)

Thanks for all the replies so far!
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of course you should take precaution... i'm just saying.. let's not get all paranoid and start doing crazy shit

other than basic touching the care or using a wrist strap... you really don't have to go any futher.. unless you reall yare paranoid i guess
 
TomMe said:
I wanted to know how components are grounded, because in the ESD FAQ someone mentioned that grounding a computer provides a safe path for current from an ESD to follow. And I also wonder why some people connect alligator clips to a computer case to ground the whole computer.

Further I'm just interested to know about grounding computers in general because sometimes I connect my computer to a non-grounded outlet out of necessity, and I'd like to know if this can cause damage to it (so to avoid it in the future). Or is grounding just for protection against electrocution?
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I have a couple points in response:

1) Your computer, and many other electrical devices have that earth conductor as protection for you. The ground is connected to the outer case of your computer/drill/saw/fan/whatever. If something live gets loose inside that case, the worst it can do is contact the grounded case and create a short. At that point, it's either the circuit breaker's responsibility or the GFCI device's responsibility to detect a fault and cut off the circuit.

2) In relation to ESD, all that ground does is bring your body's potential (or voltage) to ground. In other words, you ground yourself by touching the case when the power cord is plugged in, and at that point, you and the computer are at the same voltage. So for the moment, there is no danger from ESD. If you touch the computer case while it is unplugged, then you and the computer will be at the same voltage, but that voltage may or may not be the same as ground. Again, for the time being, there's no danger from ESD. In either case, if you (for example) shuffle your rubber-soled shoes across the carpet while not being in contact with the computer case, then there will be a voltage difference which can cause ESD damage.

It doesn't have to be as drastic as shuffling across the carpet. It can be your clothes rubbing against the plastic of the computer case bezel, or the small movements in your shoes. In that case, the charge built up is smaller, but there's still the possibility that you could build up enough to cause damage. This is why a lot of people use the wrist strap--it ensures that you and the computer are always at the same potential, so there's no danger of ESD damage.
 
Mohonri said:
I have a couple points in response:

1) Your computer, and many other electrical devices have that earth conductor as protection for you. The ground is connected to the outer case of your computer/drill/saw/fan/whatever. If something live gets loose inside that case, the worst it can do is contact the grounded case and create a short. At that point, it's either the circuit breaker's responsibility or the GFCI device's responsibility to detect a fault and cut off the circuit.

2) In relation to ESD, all that ground does is bring your body's potential (or voltage) to ground. In other words, you ground yourself by touching the case when the power cord is plugged in, and at that point, you and the computer are at the same voltage. So for the moment, there is no danger from ESD. If you touch the computer case while it is unplugged, then you and the computer will be at the same voltage, but that voltage may or may not be the same as ground. Again, for the time being, there's no danger from ESD. In either case, if you (for example) shuffle your rubber-soled shoes across the carpet while not being in contact with the computer case, then there will be a voltage difference which can cause ESD damage.

It doesn't have to be as drastic as shuffling across the carpet. It can be your clothes rubbing against the plastic of the computer case bezel, or the small movements in your shoes. In that case, the charge built up is smaller, but there's still the possibility that you could build up enough to cause damage. This is why a lot of people use the wrist strap--it ensures that you and the computer are always at the same potential, so there's no danger of ESD damage.
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indeed
 
TomMe said:
Wow.. :eek: I didn't really expect so many replies when I posted my message! Didn't expect it to turn into a pro contra ESD discussion either. :(

I wanted to know how components are grounded, because in the ESD FAQ someone mentioned that grounding a computer provides a safe path for current from an ESD to follow. And I also wonder why some people connect alligator clips to a computer case to ground the whole computer.

Further I'm just interested to know about grounding computers in general because sometimes I connect my computer to a non-grounded outlet out of necessity, and I'd like to know if this can cause damage to it (so to avoid it in the future). Or is grounding just for protection against electrocution?

I thought this might be a useful topic, so I created a separate thread about it.
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Just my 2c... If you had originally expressed your inquiries as you just did here, it would have centered the discussion on those exact points, and you may have recieved a bit better response. As it was, it kind of got piled into the recent explosion of esd threads, and a rather off-topic one at that because much of your questions as originally worded have already been addressed in the other threads.

I'm not trying to be mean, simply that imo many threads begin with rather ambiguous questions that barely mention the actual problem or the actual intent the poster needs input for. Then those trying to help have to wrangle needed info out of the poster to fully understand the issue. Better questions usually lead to better replies.

edit -

I also wanted to say I found it amusing that preventing potential pc damage resulting from being powered by an un-grounded outlet apparently ranks a higher priority than any electrocution risks LOL. At least your heart's in the right place ;)
 
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