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Myth
16-04-2005, 10:53 AM
Heyas
I'm looking for advice on ESD (static electricity).
Recently I did some hardware changes on my partners computer using usual (what I thought was sufficient ... I was wrong) precautions re static (touch psu or case every now and then to equalise). However even using care I am almost 95% sure I zapped the RAM (haven't fixed it yet, but all symptoms lead to that... BTW thankyou pctek for helping with diagnosis).
So obviously I am working in a highly static area, so to avoid zapping more RAM, or even motherboards etc; I need advice on how to kill it. I especially don't want to be zapping my mates RAM as I can't afford to keep replacing it.
I know you can get antistatic straps (wireless and wired.... how effective are these? (both wireless and wired)
What about antistatic mats, how good are these; and where can I get the mats from; and at what cost?
Any other precautions I need to consider.

Metla
16-04-2005, 11:03 AM
I use an anti-static mat wired into earth,and an anti-static wristband, I can't afford to casually destroy ram......

How effective are they?

Well, Since I saterted using the mat my peace of mind is far better.... :eek:



Where can you get em?

Just about anywhere, I can source the mats for you if your in a pinch,cost about ....hmm....Can't do bizzo on the forum, They aren't expensive and you should be able to source them locally.If not pm me and ill chuck one in the mail...

pctek
16-04-2005, 01:23 PM
I need advice on how to kill it.
I know you can get antistatic straps (wireless and wired.... how effective are these? (both wireless and wired)
What about antistatic mats, how good are these; and where can I get the mats from; and at what cost?
Any other precautions I need to consider.
How to kill it? - numerous ways, hehe.:-)
Mats are good if you have the money.
If not, get rid of the carpet! Take your socks off. Take off that fluffy nylon jumper.
What you did, having it plugged in and touching the case is good, but I'd touch it all the time, not just on occasion.
Antistatic straps that aren't connected to anything are a joke. Accomplishs nothing.
The ones you clip to something earthed are the correct way to use them.
If yyou haven't got one you can improvise and make one - the idea is just to earth yourself.
BTW Metla can you send me a PM with a price on a mat thanks? I could do with one...

Myth
16-04-2005, 01:39 PM
Thanks for that advice.

BTW Metla; read ya PM's... :cool:

Graham L
16-04-2005, 03:32 PM
It's a good rule to never touch the contacts. I've seen people who are fascinated by the shiny gold, and feel a compulsion to rub it.;) It's easy enough to handle memory sticks by the edges.

An imrovised antistatic strap should not have a direct wire connection to earth. It's electrostatic charges on your body you want to earth, not the mains. A commercial strap has a 1 megohm resistor.

Metla
16-04-2005, 05:29 PM
I just by how the TV tech in the shop next door had his,wired into the wall,are you suggesting it should be wired onto the body?...

FoxyMX
16-04-2005, 05:36 PM
I just by how the TV tech in the shop next door had his,wired into the wall,are you suggesting it should be wired onto the body?...
I was told that the wire needs to be attached to a metal part of something that is plugged in so that it is earthed. For example, hooked onto the metal back of my computer case. I hope that information is correct for the informant's sake. :D

Incidentally, do you stand on the mat or put the patient on it??

Calling Godfather... please come in!!

Metla
16-04-2005, 05:41 PM
Ok, The mat has to be earthed,not to the person.

The "person" is taken care of by a wrist strap.

The compouter sits on the mat as i work on it.

Renmoo
16-04-2005, 05:41 PM
Is it possible that you make an anti-static wrist strap your ownself? I was thinking that you tie a copper wire around your wrist and somehow stick the other end to the ground. Is that how it works? How about the idea that another person touches your back and his another hand is getting in touch with the ground constantly? :D Cheers :)

Myth
16-04-2005, 05:53 PM
I am just wondering if rubber matting would be ok to use, especially if you have carpet (that I know the landlord will object to having ripped out)?

This in conjunction with an antistatic mat

Is there any type of special matting?

Graham L
17-04-2005, 03:39 PM
Antistatic devices work by being a good path to ground. The "tech next door" will have a mat plugged into the mains socket. But there's only one wire going to the plug: to the earth pin. That is (usually) the best "earth" available. That's why a wriststrap is usually connected to a metal part of the computer (with the power plug still in, so there is an earth connection). In a proper setup, its lead will go to the mat's earth connection.

A rubber mat is an insulator, usually. Those "keyhole" shaped ones meant for office use might be slightly conductive. But it will probably be be less effective as a static generator than synthetic carpet.

Metla
17-04-2005, 03:45 PM
None of that is new,and has been covered already.

Not only has the "tech next door" got his wired into the mains,so have I, as already covered.

so.....



....weird.

zqwerty
17-04-2005, 04:19 PM
Don't connect yourself directly to the Earth, put a 1Meg resistor in series or you are putting yourself in the way of a potentially lethal shock if you touch something live and lo-impedance and over approx 50volts. The 1 Meg will bleed the static out of you but will effectively allow you to "float" if you make a mistake and touch something "HOT" as 'one is wont to do' now and again.

Myth
17-04-2005, 04:28 PM
Ummm.. Ok I know a lil bit about electricity... but aren't all the wires in an electrical outlet (plug) 'hot'? I know theres a positive, and a negative; and earth, but isn't the earth hot like the other 2?

I just want to clarify this point as I really don't want to be getting zapped if I buy a mat and wire it to the socket.

Jen
17-04-2005, 05:36 PM
I just want to clarify this point as I really don't want to be getting zapped if I buy a mat and wire it to the socket.If you are just fixing the odd mates PC's, then you probably be will fine just with a anti-static wrist strap - that is all I ever use. As long as you remember to unclip yourself before jumping up to answer the phone, you should be right :p.

Not sure if I remember this correctly, but if you use the anti-static bags that components arrive in to lay things on to protect them while they are out of the case, is this good or bad? Thought I remember someone once saying that you can get static off the outside of the bag and only the interior is static free? Or have I got that wrong :confused:

Greg
17-04-2005, 05:47 PM
Really all you need is an anti static wrist strap, attached to the case, which is plugged into the wall, with the wall power switched off.

godfather
17-04-2005, 06:00 PM
Ummm.. Ok I know a lil bit about electricity... but aren't all the wires in an electrical outlet (plug) 'hot'? I know theres a positive, and a negative; and earth, but isn't the earth hot like the other 2?

I just want to clarify this point as I really don't want to be getting zapped if I buy a mat and wire it to the socket.

There is no "positive and negative", they are DC power terms.

There is a Phase (or Active) and a Neutral, plus an Earth.

The Neutral and Earth are connected together (and to actual earth, such as a driven earth stake into the ground) back at the main switchboard, only the Phase is "live", assuming all wiring is in order.

I have dealt with static sensitive components since the 1970's (when the chips were very sensitive to destruction).
In many cases it simply was not possible to use static protection in the field.

In all that time I have never managed to destroy a component by static, so I am unsure how you succeeded in doing so with such apparent ease!

I find that just using a wrist strap is adequate, you are simply making sure that both you and the computer are at the same potential for most tasks, it matters little if that potential is "earth" or not.

Myth
17-04-2005, 07:00 PM
In all that time I have never managed to destroy a component by static, so I am unsure how you succeeded in doing so with such apparent ease! Trust me, I'm still scratching my head wondering how as well.
When at my course its like I can do no wrong... (made a brand new machine with $1200 worth of parts this last week .. had 3200 AMD and Geil RAM... no probs) but when Im at home taking the same precautions; I only have to open the case and bang :( ... hence why this thread. The only difference was I was wearing jandals at course, and bare feet here.. hence the question on rubber matting. Both places have carpetting on the floor... so its a process of elimination, and then how to fix or change this environment so I can do hardware changes/repairs etc safely

Metla
17-04-2005, 07:13 PM
Precautions are good, even if they are never needed, its better then not having them. Strange that some would dismiss something that is practical and worthwhile.

Perhaps you would remove the bumpers off your car because you have never hit anything?,and at the same time question how others hit things with such apperent ease.

Myth
20-04-2005, 04:22 PM
Seems I may not have a static overload after all :blush: :cool:

Finally managed to get around to fixing partners comp... with techs help (parts wise) at course, I ascertained my partners mobo has crapped out.
As for my comp (I opened comp case last nite to replace IDE cable; started up.. no boot (again) with audible warning) I took that into my old technician. She thinks shes found the problem; a faulty USB plugin controller; that was shorting out and sending errors to the CPU. Apparently when that happened, the RAM would stop, and had to be physically taken out and then replaced before it went. Something about the MSI mobo I have.

To think, I had new RAM put in 2 weeks ago and threw out 'faulty' one

Metla
20-04-2005, 04:24 PM
ah well,here's the promised photo of such a mat.

http://www.computermedic.co.nz/images/matattack.jpg