Magnetic screwdrivers and a computer

[MartinW]

Is it safe to use magnetic screwdrivers on a computer when it's off?

Martin

[andytheboa]

it may damige the hard drive.

[marisa]

No it will not. Even using one while it's ON won't mess it up.

A harddrive ITSELF using magnets like 100X stronger than the screwdriver. My boyfriend has been working on computers with these screwdrivers for over ten years now, included his job a couple years ago as an actual tech.

Marisa

[andytheboa]

Oh sorry. :0

[Samba]

I think the only problem with magnets is they can erase information stored on FLOPPY disks... I don't think they have an effect on any other devices... =)

[MartinW]

That's good news:) Now if only I could remember where I put the damn things!

Martin

[Siretsap]

It won't cause any problems. The main problems I have seen when working with pc's is if you don't unplug the power cord. I was working on a pc with a friend and a static discharge from his finger in the case caused the pc to boot up!!! :-) Was funny as hell cause the discharge made his arm move back.

I even tried putting a whole chess set (magnet pieces) on a hard drive and boot it up and let it run for hours without any problems.

The only thing I had success wiping was a floppy using a fridge magnet (the usually ugly ones you get in the mail ).

[Invictus]

I've been working on PCs for over 15 years, and I can tell you that magnetic screwdrivers CAN and DO erase hard drives. Worse yet is the damage they can do to the chipsets on motherboards, controller cards, etc. I once shorted out an entire motherboard because of a magnetic screwdriver. They teach you this in the A+ certification courses. A magnet like those found in magnetic screwdrivers is actually several times more powerful than the magnetic surface of a hard drive, and it is positively charged. When it comes near enough to the surface of a hard disk to cause a charge, the data that is stored on the disk can get scrambled beyond recognition. Remember, it's being held there by a magnetic surface as well, but a weaker one.

Some chipsets include what is called firmware - just like software, except that it is coded right into the chip, so the chip knows its own function. This can also get seriously jumbled up by a magnetic screwdriver.

This is why actual PC repair kits come standard with non-magnetic screwdrivers. I bought a whole set of non-magnetic just for the purpose of working on computers.

[heebie_geebies]

It would be safer for you computer if you leave the power cord plugged in. That will let the static discharges go to ground instead of building up potential in your PC. Just make sure you turn off the main power switch that is on the power supply, or if you don't have one of those, the power bar. After that is off, press the power button on the front of the PC to discharge the capacitors in the power supply. LEDs will probably blink, and then that is it, no more power and a safe, grounded computer to work on.

And just a tid bit of info on ESD (Electro-Static Discharge), circuits can be damaged by 100V or even smaller. Humans cannot feel a shock less than approximately 3000V.

[Cruciform]

It's not the magnetic screwdriver that damages the hard drives. A hard drive can be exposed to the field of a VHS tape bulk eraser and survive unscathed.

Like Lyndon said though, static is a dangerous enemy. If the screwdriver picks up a charge from you and you get to close to the wrong chip or solder point -- ZAP!

The numbers I've heard regarding static were 300v for hardware, and 1500 to register on a nerve ending. Either way, if you feel it the computer felt it first.

Grounding is important, so either wear a grounding strap on your wrist or keep part of the arm that's inside the machine grounded against the case. *DON'T* use your other hand/arm as a ground. If there's current still available it will travel across your chest and kill you. One of the founders of the search engine that loads on the side of sSnakeSs died of electrocution while fixing his computer.

[Siretsap]

Lol wanted to bring my subject to that strap and forgot to mention that strap, even if it looks kinda gay, it is best to have it. The part I hate about it, is the wire that has the pliers (you usualyl plus to the frame of your computer) well this wire tends to always get in your way, either it is to plug in more memory, move your wires around, it always seems to get in the way.

[ib_inked]

The best way to ground yourself when working on the internals of a pc is to touch the metal case inside first. It will not damage the components inside if you do this. I build computers on a weekly basis, and I use a grounding bracelet. That being said, when I go to someones house to fix their PC I never use the grounding wire, simply the metal case inside to discharge any static electricity.
I've been doing this for 15 years as well without incident.
As per the magnetic screwdriver, I have used them, there is never really a need to put it close enought to the HD to damage it, unless of course you are installing it. I have installed HD's with a magnetic screwdriver and have never had incident, but I may have been just lucky.
Any A+ book is good for info like this as Invictus said.

[heebie_geebies]

Originally posted by ib_inked
The best way to ground yourself when working on the internals of a pc is to touch the metal case inside first.

Yes that is correct, as long as the case is still connected to a ground source (three-prong wall plug). The metal case standing alone on a table is not a ground point. Touching the case while it is not grounded will only bring you and the computer to the same potential. That helps, but at some time, that potential energy on the PC will have to be discharged somewhere, and it may not be controlled.

And to avoid the problems with a wrist strap cord getting in the way, try it as an ankle strap. It will work as long as you got the metal part of the strap on your bare skin.

[Derrick]

Originally posted by Invictus
I once shorted out an entire motherboard because of a magnetic screwdriver.

hehe shorting it out had nooting to do ith the fact that the screwdriver was magnetic. You can short it out with anything contuctive while its powered up, like water or a fork. I just stuck my 3 magnetic screwdrivers on my primary harddrive, not on the circut board mind you casuse that would risk shorting it out, and will leave them there for a few days I am that confident the wont mess with my data.

I will never work on a computer with out a set of good an strong magnetic drivers. It sure beats digging out those screws from the nooks and cranies

[marisa]

Well like I said, my boyfriend has been working on computers professionally for years, and has NEVER EVER had a problem with a magnetic screwdriver....ever.......

But to each their own.

Marisa

[Stockwell]

Yeah, I agree magnetized screw drivers are fine and far better than dropping a screw across the legs of a chip or capacitor, especially since they sometimes tend to disappear. Hard drives are in steel cases and thus protected from outside magnetic fields. But of course putting a magnet on a plastic floppy disc will mess it up.
I work with both magnets and mos semiconductors every day.. My biggest problem is the strip on my damn charge cards never works.:) One should be careful not to put magets in the same pocket as your wallet.
My wife recently bought a purse with a mangetic clasp right across where you are supposed to put your credit cards.. That has to be the dumbest thing I've seen in a while.
One minor correction on the level of voltage one can feel. That all depends on the conductivety of your skin at the contact point, and the overall resistance of the complete cicuit path from plus to minus or live to ground.
If you stick a 9 volt battery across your wet tongue, you'll feel it, and 120volts is responsible for lots of north American electrocution deaths, so the above info stating it takes 1500 volts to register in a nerve ending... is incorrect.( as an electrical worker, I wish)
Its not always the shock that kills you, its the fall from the ladder

[Invictus]

Unky Roy, is there anything you're NOT a guru of? lol

[Kimo]

Last i read in a book...(was some sort of hacker that went public)
was that you needed a serious magnet like the back end of a subwoofer for example to whipe a comp, now this could be false info, but the above mentione hacker, said he used this methond to save his ***...once again tho, could be false info...wish i could remember the name of the book?

Josh

[Linds]

Originally posted by Stockwell
My wife recently bought a purse with a mangetic clasp right across where you are supposed to put your credit cards.. That has to be the dumbest thing I've seen in a while.


That's what I had always thought about those things, but they were tested on mythbusters and shown to be inneffective, as well fridge magnets, other cards, etc. They tested a big stack of cards, and it took a lot of power to damage the cards. I can't recall whether it was an abnormally strong magnetic field or voltage they were using, that eventually damaged the cards, but hopefully someone else on here saw that episode. I can't remember what the likely culprit was in the erased cards problems that people experience either... :confused: It was the myth that an eel skin wallet was capable or erasing the cards.

[heebie_geebies]

I did say 3000V was approximate for a human to feel a static event. And perhaps I should have put "to feel discomfort". I 'm sure some studies would probably go +/-1500V of the previous mentioned level. It depends on many variables such as body location of the discharge, humidity and your own sensitivity. But the reason the high voltage doesn't cause too much harm is that the current is miniscule. If I remember right, dragging your feet across the carpet then "zapping" someone is about 25,000V!!

The main idea for stating the levels was to point out that even though you cannot feel a static shock, does not mean it didn't happen.

Where is this all coming from you might ask? Myself, I have a technologist diploma and have been working as such in a electronics manufacturing environment for 6 years. Currently sitting as a Quality Analyst, ESD is a daily concern for me. I have had to sit through, I'm guessing, 10 hours of ESD specific training. (In those 10 hours, I'd never thought I would be talking about ESD outside of work though. sheesh!!). I too was shocked at those numbers, but there has been millions of dollars spent on research on this topic. Reason for that is there has been billions of dollars lost through ESD damage. I know this is not what the thread was started on, my apologies. I have very little experience when it comes to reptiles, but I do know ESD.

As for magnetic screwdrivers, I don't use them. I stick a hunk of tape or even a hunk of my gum to hold the screws if necessary. Why risk it if you don't have too?

[Cruciform]

Stockwell, sorry, I should have clarified - 1500 volts of static charge jumping from a surface to your skin.

Anyone who has grabbed an electric fence knows you don't need 1500 volts to feel that :D

Then there's the experiements with high voltage low-amperage electricity where you can have 250,000 volts dancing across your skin and all you feel is a tingle :)

[Ixidor]

my head hurts :(