Your Sneakers Can Kill Your Computer: How Static Electricity Works
Static electricity is the number one computer hardware killer, and its everywhere! Panic aside, if you do any work with computer components – even as simple as upgrading your memory – you need to know what static electricity is, how it can damage your PC, and how to prevent problems occurring in the first place.
What is static electricity?
Most things don’t have an electrical charge – meaning they don’t zap you when you touch them – and that’s because they have a balanced number of electrons (a negative charge) and protons (a positive charge). However, when two surfaces rub together, electrons are “scraped off” and attach to the other surface. Since some surfaces lose their electrons more easily that others, you can end up with an imbalance – when one surface has more or less electrons than it would have normally. Rubber things are particular susceptible – balloons, or sneakers – for example.
Static electrons remain on the surface of the item until they can be neutralised somehow. One common experiment for demonstrating this power is to rub a balloon against the carpet or your jumper, then make it stick against the wall – the negatively charged balloon is electro-statically “attracted” to the positive charge of the wall.
Why is it dangerous to computer hardware?
Sometimes, this electro-static charge will jump suddenly from one charged material to another – something which conducts electricity. When a human body becomes charged, this can often result in a small electrical shock when you touch someone. It also occurs on elevators – you’ve been walking around, creating an electrical charge – then you suddenly touch the metal area under the handrail. The shock is a mild discomfort, but certainly not harmful. However, if that discharge of electricity (called Electrostatic Discharge or ESD) goes to computer components, which are semi-conductors, permanent damage can occur. Even if a physical spark is not seen, smaller discharges can cause significant damage too.
Unfortunately, damage from static electricity – electrostatic discharge – is also the hardest to diagnose. Since it leaves no visible damage (at least, at the level we’re talking about), it merely presents itself as erratic behaviour – random errors – that may occur anytime, without repetition and without an obvious pattern. Your CPU may return incorrect calculations; your memory may flip certain bits and become corrupt. It may be an error that your computer can easily overcome with error checking processes that automatically correct these kind of events; or it may cause a critical blue screen of death and immediate restart. You might refer to these as gremlins in the machine, but the real demon here is often ESD.
Prevention then, is the key to avoid ESD damage.
How can I prevent ESD damage?
The basic message to take home today is that before you touch any electrical components – computers or otherwise – you should discharge yourself of any static electrical energy. If you’re working inside your PC – upgrading or replacing parts – this can be achieved easily by wearing an anti-static wristband. These are no more than electrical conductors that “ground” you and provide an outlet for the electrical charge to dissipate. Attach the wrist band to yourself and the other end to a radiator, or to the metal computer case itself, provided it’s plugged in to the electrical supply but not actually turned on.
Another method is to simply touch a radiator, though this isn’t as reliable. Remember that if your radiator isn’t right next to your PC, you’re going to be building more static electricity walking back over to your PC!
In addition, don’t wear a wooly jumper – these are really good at creating static charge with every movement.
Of course, you can’t walk around connected to a wrist strap all day though, so what above when you’re moving or carrying components and hardware? In that case, you should always use an anti-static bag. They look like this, or sometimes just a foil bag:
Those lines you see are electrically conductive, and the conductive mesh creates what is known scientifically as a Faraday Cage. These protect anything inside the bag by absorbing(or to be more accurate, redistributing) electrical charge on the outside. You’ll know exactly how this works if you’ve ever been in a car or aeroplane that’s been hit by lighting – the huge electrical charge won’t have transferred itself to you.
I hope this has been informative for you. The trouble with explaining that static electricity is harmful to computers is that you can’t really see it, and problems may not manifest themselves for weeks, nor as anything specific. In fact, this article is probably going to get some comments along the lines of “well, I’ve never discharged myself or worn a wrist-strap, and my computer’s fine!” – but they’re wrong, and you’d be best ignoring them. The damage does occur, and it does cause problems, and you will end up with gremlins in your PC. Play carefully with hardware!