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Amiga computer related discussion => General chat about Amiga topics => Topic started by: Super TWiT on May 24, 2010, 04:12:06 PM
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When I am inside my amiga 500, I attach the alligator clip of my wrist strap to the floppy drive casing, where the keyboard is grounded. I don't leave computers plugged in when I work on them because I feel the risk is greater that you short something due to unrealized electricity, and prefer to subscribe to the theory that because you clipped yourself to the computer you and the computer are at the same static potential. But today I thought "I really want to be at the same static potential as the components I am working on, not the case. How can this be effective?" Could someone answer my question?
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Just about all chips require a ground connection, so that'll make sure the differential between electronic components and case ground is very close to zero.
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Even the casing of a floppy drive?
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I have never ever in my enitre life used a strap and have never had anything damage, even over time.
Find just grounding myself on some heating pipes first is sufficient.
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Same here-I touch something like a sink faucet. I also live in an area that has little to no static buildup (PNW), tho :)
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Part of my job is hardware support of PC's and Server equipment. It is a very good practice to ground yourself when working on equipment. For those that say you have never hurt your equipment before, you may be correct.. And you also may be wrong. Unfortunately, the damage can be done to chips without being noticeable for months... (Really, no kidding) Then all of a sudden the chip goes kaplooey. (Technical term that i may just copyright soon. :O)
Anyway, grounding is a good idea, but if you don't plug the PC into the wall socket you are not truly grounded at all and have wasted your time with the alligator clip... The ground must be plugged into a wall socket to work, so here is a trick I learned years ago. Take a standard three prong plug and remove both prongs from it with a pair of pliers.. Be sure to LEAVE the ground prong.. Now when you plug it in, only the ground is plugged in and your machine is fully grounded. Now take your gator clip and clip it to the frame of the machine. (Don't trust the floppy drive as you may not have a good connection to the frame... Also you don't know if the floppy is aluminum.. If it is you won't get any ground off it.)
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I can't really sand down the power connector on an amiga though, but that is a good tip for pcs with interchangeable cords. I was just wondering how the case and computer components could be at the same static potential? By the way, the amiga 500s keyboard is actually grounded to the floppy drive case by way of a screw on cable, so I assume it is a good grounding point.
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By the way, the amiga 500s keyboard is actually grounded to the floppy drive case by way of a screw on cable, so I assume it is a good grounding point.
Good point... That should be a good ground then... But only if the plug is plugged into the wall...
Hmmmm.. Not really sure how to ground that one without the removable cord. (I have a 2000 and it does have the removable cord)
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I have never ever used any protection against static electricity.
I have "built" my own computers since i was a young teen in the 90s and yet never any harm done. I have also picked up hardware at the local scrapyard/electronic rycycling center and even the motherboards i found laying lose in containers and such worked just fine.
I think the risk of static damage is highly exaggerated, but i guess it is never a bad idea to be extra careful with rare or expensive hardware.
I also often find ram and such recycling centers and generally just put them into my pockets without any kind of static bag and yet those ram sticks worked just fine.
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Part of my job is hardware support of PC's and Server equipment. It is a very good practice to ground yourself when working on equipment. For those that say you have never hurt your equipment before, you may be correct.. And you also may be wrong. Unfortunately, the damage can be done to chips without being noticeable for months... (Really, no kidding) Then all of a sudden the chip goes kaplooey. (Technical term that i may just copyright soon. :O)
Anyway, grounding is a good idea, but if you don't plug the PC into the wall socket you are not truly grounded at all and have wasted your time with the alligator clip... The ground must be plugged into a wall socket to work, so here is a trick I learned years ago. Take a standard three prong plug and remove both prongs from it with a pair of pliers.. Be sure to LEAVE the ground prong.. Now when you plug it in, only the ground is plugged in and your machine is fully grounded. Now take your gator clip and clip it to the frame of the machine. (Don't trust the floppy drive as you may not have a good connection to the frame... Also you don't know if the floppy is aluminum.. If it is you won't get any ground off it.)
Either way i have never had hardware except for PSU or hard drives die on me which was completely unrelated. Even the mobo i told about in my previous post i used for years with no stability problems even though both ram, sound card and mobo was all found in trash.
The pc i am currently using has a audigy ZS 2 card i found laying in a muddy water pit and it worked just fine after some cleaning and has not caused any stability issues whatsoever.
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Either way i have never had hardware except for PSU or hard drives die on me which was completely unrelated. Even the mobo i told about in my previous post i used for years with no stability problems even though both ram, sound card and mobo was all found in trash.
The pc i am currently using has a audigy ZS 2 card i found laying in a muddy water pit and it worked just fine after some cleaning and has not caused any stability issues whatsoever.
Yep and everyone has to make their own decisions about such things, but multiple training courses and books etc. from different companies that actually manufacture the equipment all state that this is a legitimate issue. My personal opinion is that if the folks that create the stuff says it can be an issue I will defer to their expert advice rather than someone that has simply been "lucky"...
But who the Hell am I? We all know those certs and courses and 20+ years of experience is just fluff anyway right?
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My personal opinion is that if the folks that create the stuff says it can be an issue I will defer to their expert advice rather than someone that has simply been "lucky"...
But who the Hell am I? We all know those certs and courses and 20+ years of experience is just fluff anyway right?
No, it is definitely not "fluff" and you are right to take precautions against static electricity. The danger is very real, and can be tested very easily. As you mentioned in one of your previous replies, it is possible to compromise a component by static discharge, rather than outright destroy it. Indeed, I would suggest that this form of damage by poor handling is the most common. After the component has been compromised, its reliability and long term life will have been reduced. The amount to which the life has been reduced depends upon many factors, including but in no way limited to the strength of the static discharge itself.
A lot of people will use the argument that they've been building electronics stuff for years without taking precautions and have never had a problem, but there is no way of verifying such statements. A component that fails 6 months or even years down the line after providing reliable service up to that point will not be attributed to a static discharge due to poor handling because of the length of time that has passed. But this does not mean that the problem was not caused by static discharge, it just means that the component's life may have been reduced, the result of which was premature failure. A failure that would not have occurred had static precautions been taken.
I have seen evidence of the damage caused by static discharge, and I have also tested it myself. It does happen. Of course, it is possible to disregard anti-static precautions and see no ill effects, but why take the risk when a wrist strap and grounding point is so cheap to buy? If you handle electronics components regularly and you don't take precautions then it's only a matter of time before damage results. It doesn't make sense to take such risks in my opinion.
AH.
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I have never ever in my enitre life used a strap and have never had anything damage, even over time.
Find just grounding myself on some heating pipes first is sufficient.
Yep, I would agree with this. Grounding yourself on heating pipes is a valid precaution to take against static build up. It's not as ideal as a wrist strap because a wrist strap will constantly protect against a static build up, but provided you ground yourself every time you sit down at your work desk and before you handle the board then the likelihood of static damage is greatly reduced.
AH.
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Even the casing of a floppy drive?
If you look closely you'll see that the two standoffs on the rear of the floppy go to two large pads on the mobo that are connected to ground. Electronics works way better if everything is severely grounded. ;)
While we're at it: the thin metal shield around the mobo provides very good grounding. As has been mentioned, the drive may provide no reliable ground for an alligator clip due to paint/oxydization even though it's grounded.
I usually keep the wall socket plugged in but switch off the mains switch. That way grounding is intact while no power whatsoever is to be found. While working on the machine I stay in contact or very frequently touch metal parts. Also, not shuffling your feet and handling delicate parts by the edges only ensures that your stuff runs reliable for some time to come.
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To not ground yourself is just asking for a problem! Ground yourself to the best ground available, usually your properly grounded outlet - with a good quality wrist strap.
You would be amazed at how much voltage a static charge can have. The other values are usually very low, but this is enough to fry many chip types instantly.
I am always amazed at people who love to play with fire...
PS - 50,000 volts is possible! - 25,000 is fairly common. Think your chips can take that?
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I would also advise advise caution regarding static electricity.... One thing to mention, some of the posters have said that they have never had any trouble with static electricity, despite taking no precautions.... Well, the type of carpeting you have in your house, even the climate in your area can play a part in static buildup.
Also, without lab tests done, the results posted here, and verified.... We really don't know what could have killed that component/RAM/etc. Any number of variables could have made a difference.....
Static electricity? Old age? Bad Luck? Carelessness? Evil Martian Flingoes?
Zac67 gives some helpful advice, IMHO
My 'workbench' ( I mean the place I work on computers, etc. ... not the Amiga Workbench ;) )is my kitchen table (best light) and so gives me easy access to a ground, the faucet :)
And, I also touch boards/RAM from the outer edges whenever possible.
Just my 2 milliamps....
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If it is connected to the floppy casing that is okay for ground. Shiny metal would be slightly better. It provides a nicer path for any static build up to flow to, as opposed to your finger.
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Static is a quite legitimate issue alright! Though I often don't use a wrist strap. When you say the components are the same potential as the casing, I take it you understand we're talking about the metal casing, and that clipping yourself to the plastic case of an Amiga 500 or 1200 won't do any good at all. The amount of static present on your body is down to a wide variety of factors - the clothes you wear, the climate you live in, your shoes, the floor and desk materials, and so on. Such high voltages exist that they can easily damage components by flowing through them to ground. Strapping yourself to the casing whether it's connected to ground or not will decrease the risk of damage as you and the case are both then at the same potential, meaning very little charge can move through your parts. But really you should be grounded to a proper ground as well, whether through the mains lead of the computer or through a special grounding plug.
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I take static very seriously. The humidity is at least 33% mostly higher. I usually ground myself by touching a grounding screw which is right in the room where I work on the amiga. I also touch the tap (sink faucet). I usually wear 100% cotton (socks included) when working on the amiga (cotton is static neutral along with steel). I also walk across no carpet flooring. And, I work on a hardwood floor which is VERY close to being static neutral (wood is slightly positve). On top of it all, I wear a wrist strap. :)
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Good point... That should be a good ground then... But only if the plug is plugged into the wall...
Hmmmm.. Not really sure how to ground that one without the removable cord. (I have a 2000 and it does have the removable cord)
I know how to ground it! Get an extension cord and modify that! Then plug the amiga into the extension cord and the modified extension cord into the wall.
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@outlawal2
Just some additional notes.
"The ground must be plugged into a wall socket to work"
Ant the wall socket has to be grounded. (in Norway not all of the wall sockets are grounded. specially in older homes)
"Take a standard three prong plug and remove both prongs from it...."
No need to do that. Most moder PSU have a power switch. it only breakes the power leads. Ground leads are always connected. (And that is a part of European standards for electronic equipment.)
The same goes for Amiga PSU, the shield ground is always connected...
Abd a question:
"Also you don't know if the floppy is aluminum.. If it is you won't get any ground off it"
Why not?
Aluminum is a good electric conductor...
I have speaker cables made of aluminum.
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Now, I have another question (sorry for the hmm.. lets see TRIPPLE post) I hear you can turn off the power supply and leave it plugged in and the ground will still be effective. Wouldn't the switch break the connection between you and the ground?
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I might still mod the plug because I don't really trust the switch all the time. I probably will switch it off & plug in the modded plug. I bought a ground tester, and was surprised to find all the outlets were properly grounded. This house was built in the 70s and well some of the wiring looks a little scary. Also, according to my multimeter voltage is pretty good too. Well, I guess maybe the wiring ain't so bad after all.
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@ marcfrick2112
If i can, i take precautions. Specially on new expensive hardware.
However. i have tried older hardware.
Among them an old P90
I used it as a "cam", calming my hair.
I could hear the sounds of the static discharge....:crazy:
But the devil still works......(!)
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I have a question about the plug I bought. I got a cheap one from walmart, and I am noticed it has a label on the side that says 125 volts US. Static electricity is thousands of volts. I assume this is still okay to use. (its 16 awg wire).
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Don't mean to drudge up an old thread. I guess I can't help but ask yet another static electricity question! :laughing:
Anyway, from what I've gathered here, people are telling me that in order for static electricity prevention to be effective, I need to have my wrist strap clipped to a grounded spot on my case, and the computer plugged into a grounded outlet.
However, assuming I don't plug it in but I do have my wrist strap clipped onto my case, won't electrons just build up on the case, and then once I plug in the computer the electrons will flow to ground. If so, what is the harm in not plugging the computer in while I work on it?
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The only thought about the static electricity question that comes to my mind is what if I
carry my computer in my pocket? Walking around in corduroy pants and dragging my feet on
my shag carpet day in and day out.
I've had a cells phones for 10+years. I usually carry them in a pocket. Countless times I've
zapped my phones. I've never had a phone die. A cell phone isn't grounded, sits in your
static filled clothes, just seems like if there was a big issue with static cells phones would be
dieing left and right for no noticeable reason.
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Easy solution: Buy an anti-static interface that connects to the mains socket. Job done.
If you're a bit of a cheap skate like I am, then you can make your own. You just need to find an old mains plug, take out any connection to live and neutral, and connect a single cable to the earth pin via a 1M resistor. This cable then becomes your anti-static wrist strap earthing point. If you terminate it with a 4mm banana socket then your wrist strap will plug straight into it.
Of course, I can't recommend that solution unless you have experience with electrics and know what you're doing. If you don't know what you're doing then you're better off just buying an adaptor from an electronics store - they're only a couple of quid (dollars) anyway.
AH.
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A cell phone isn't grounded, sits in your
static filled clothes, just seems like if there was a big issue with static cells phones would be
dieing left and right for no noticeable reason.
Static electricity is more of a concern when you're handling exposed components rather than when you're handling completed circuit boards. Also, your cell phone is encased in a plastic enclosure which is an insulator. This makes it less prone to damage from static electricity than if you carried the exposed PCB in your pocket instead.
The exposed connectors on the cell phone are usually shielded with a ground plane so a static discharge here is most likely to go to ground than via a semiconductor.
AH.
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What I was wondering about was why can't you have your wrist strap clipped to your case, but just not have it plugged in. Electrons would just build on the case right? If so, what's the problem with that?
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By the way, if anyone has any doubts about the damage that can be caused by static electricity try the following:
1. Set up a simple CMOS IC based circuit on breadboard. A simple binary counter circuit or something like that. You'll find such circuits in any beginner's electronics book.
2. Check the circuit to make sure it works.
3.Take the CMOS counter IC out of the circuit.
4. Find yourself some wooly clothing and build a static charge on yourself by rubbing the clothing together. Alternatively you can rub your hands over an old CRT monitor while you switch it on from cold.
5. Once you've built up a nice static charge, touch one finger onto the CMOS IC.
6. Plug the IC back into your previously working circuit. My guess is, it'll be dead as a door nail. This is an extreme case where you've purposely built up a big static charge on yourself and immediately discharged it through an IC. But there are many "in-between" states where you'll have inadvertently built up a charge on yourself and you compromise the device you handle instead. It's this case that shows no immediate symptoms but reduces the life span of the device.
AH.
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I don't doubt static electricity is dangerous. I just wondered what the problem was if I didn't plug in the computer to ground while I worked on it, but had my wrist strap clipped to the case. Even though the case isn't grounded, all that would happen is electrons would build up on the case right? Where's the harm in that? They would dissipate the next time I plugged the computer into a grounded outlet.
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I don't doubt static electricity is dangerous. I just wondered what the problem was if I didn't plug in the computer to ground while I worked on it, but had my wrist strap clipped to the case. Even though the case isn't grounded, all that would happen is electrons would build up on the case right? Where's the harm in that? They would dissipate the next time I plugged the computer into a grounded outlet.
Electricity just wants to follow the path of least resistance to ground. The safest thing to do is just ground everything which in this case is you and the machine.
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I just have a power cord with only ground wire in it and this goes into the PSU and the other end in the wall socket which in the entire house are all grounded.
I keep one hand on the case when I insert or take out a card and I haven't blown any of my own.
I have however blown a videocard in the early days on the pc of one of my friends with static.
He reteurned it and got a new one :roflmao:
On the Amiga the 1084 monitor is one of the main reasons for blowing Amiga's since this is only uses live and neutral and is not grounded.
And when you connect the RGB connector to your Amiga while the monitor is on you can probably see little sparks when it touches the video connector on the Amiga.
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Static is serious...but..only if you are handling devices that are not "buffered", since tri-state buffering 99% of IC's arent "that" static sensitive.
Just make sure you keep the IC's in tin foil wrapped polystyrene or proper anti-static bags or conductive foam. Handle with care and ground the chip on the case or keep it in-socket and all will be well.
There is really, No need for straps or other crazy mats or stuff. Your more likely to break the pins or bend them the wrong way, because your wrist strap snags on a case ;)
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One small point, if you're going to ground yourself to a low-impedance source, like mains earth or a metal case, then do it through a high-value resistor, so that if you do accidentally touch a high-voltage circuit you don't end up fried.
Even better, use one of these:
http://en.wikipedia.org/wiki/Antistatic_wrist_strap
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then do it through a high-value resistor
U have shoes don't u ?
If you are planning to commit suicide by electricity, and earth strap isn't going to stop that.
Your more likely decrease your resistance and conduct across from hand to hand through the heart. Smokin..... ;)
Warning: For Education purposes only. Do not watch if you a minor ! Just google it later.
http://www.liveleak.com/view?i=fc0_1243424473
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One small point, if you're going to ground yourself to a low-impedance source, like mains earth or a metal case, then do it through a high-value resistor, so that if you do accidentally touch a high-voltage circuit you don't end up fried.
Even better, use one of these:
http://en.wikipedia.org/wiki/Antistatic_wrist_strap
Never seen a commercial wrist strap that didn't incorporate a resistor in it. Not really for your worry though...
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other what already said, pay attention on what you are dressing while doing services (electronics services i mean:-))
On a side note, consider that if you are working in a known/safe enviroment (like your own bench) is a matter while if you are out for servicing fe a server or such, in an unknown enviroment (at least for you) is all another matter (above all the gears you working on, are not yours) :-)
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Static is serious...but..only if you are handling devices that are not "buffered", since tri-state buffering 99% of IC's arent "that" static sensitive.
Just make sure you keep the IC's in tin foil wrapped polystyrene or proper anti-static bags or conductive foam. Handle with care and ground the chip on the case or keep it in-socket and all will be well.
There is really, No need for straps or other crazy mats or stuff. Your more likely to break the pins or bend them the wrong way, because your wrist strap snags on a case ;)
If you ground the chip on the case, then touch the pins with your fingers you can still destroy it. What good is grounding the chip? The chip isn't where the static is, you are! And tri-state outputs are still semiconductor driven, and can still break down very quickly when their maximum voltage is exceeded. And static is well beyond their rated maximum.
To answer the other question, if you and the case are at the same potential, i.e. you're connected to the case with a strap, then the static is not going to be a problem unless the chip or whatever comes near to contact with an actual ground while you're touching it - which is probably unlikely. It greatly reduces the risk, but to be sure you're still better off having the case and yourself grounded.
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I just have a power cord with only ground wire in it and this goes into the PSU and the other end in the wall socket which in the entire house are all grounded.
I keep one hand on the case when I insert or take out a card and I haven't blown any of my own.
I have however blown a videocard in the early days on the pc of one of my friends with static.
He reteurned it and got a new one :roflmao:
On the Amiga the 1084 monitor is one of the main reasons for blowing Amiga's since this is only uses live and neutral and is not grounded.
And when you connect the RGB connector to your Amiga while the monitor is on you can probably see little sparks when it touches the video connector on the Amiga.
Grounding the whole unit this way is the safest for your computer. But you've gotta be 100% sure you are safe yourself. Even having an AC plug with an earth only (to ground your unit for maintenance) has a certain level of risk
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Grounding the whole unit this way is the safest for your computer. But you've gotta be 100% sure you are safe yourself. Even having an AC plug with an earth only (to ground your unit for maintenance) has a certain level of risk
I'm a certified engineer in replacing electric meters and gas meters, I'm used to working with live wires that supply 3 x 400 volt and between neutural 3 x 230 volts, so I know a bit about voltage and currents and static electricity :)
Have had my share of shockings.