Randolph Apple’s MacBooks and iPads, and Microsoft’s Surfaces, have blurred the lines between “computer” and “personal electronic device”, so I feel like we’ve forgotten about those things on our desks at work with Dell or HP written on them.
Desktop computers, sometimes called towers, are sensitive snowflakes, with very narrow margins for error. That’s why redundancy is a big part of keeping computers up and running, especially in corporate environments.
I wrote an email to a friend of mine about ten years ago, who was having desktop computer issues. What follows is a lightly edited transcript of that email.
The tone is conversational, and is not meant to be precise.
A motherboard runs at 12 volts. If you don’t supply enough electricity to the board, it can destroy the hard drive because it needs enough current to move the electrons in order to power the motor of the mechanical drive. If you supply too much, it can blow up bits of electronics and destroy the hard drive. Under-voltage or over-voltage is in the order of 0.5V. A solid-state drive is less prone to failure from under-volting, but will suffer the same fate from over-volting as other components with no moving parts.
A PSU (power supply unit) takes in 110V (240V where I come from) and transforms it into 12V (using a big-ass copper coil over a piece of steel, a.k.a an electromagnet).
An older PSU, say 2 to 3 years old depending on its living conditions (18 months in Saskatchewan because of the dust), will start causing issues by providing an inconsistent current to the motherboard.
Different components on the motherboard run at either 3.3V or 5V. They can blow out with a difference of between 0.1V and 0.3V. Depends on the age of the component, the age of the motherboard, the age of the power supply, the direction the wind is blowing on the Rockies, etc.
An electrostatic discharge happens every time the computer turns off. An electrostatic charge happens every time a computer turns on. We recommend leaving a PC running because it’s safer for the electrical components, especially hard drives. We also recommend never handling the computer without being safely grounded first. An electrostatic discharge from dry air and walking on a carpet can cause up to a 25,000V (not a typo) charge.
Here’s something interesting: the CPU fan collects dust, because it’s an electric motor, and an electric motor has an electric charge, and dust particles have an electric charge. Over time, dust bunnies can develop between the fins of a CPU heat sink, between the heat sink and the fan, as well as in the gaps between the blades of the fan. The CPU fan has a very low resistance, so with all that interference from dust, it eventually stops removing heat from the heat sink. This makes the CPU itself overheat, which (on newer computers anyway) either causes the machine to freeze (ho ho, funny word for overheating), or on older systems literally cooks the CPU, and the silicon in it melts. Neither of these outcomes is good for productivity.
That’s not even the interesting part! People recognize that a CPU fan might get dusty, so they bring out a trusty vacuum cleaner. A vacuum cleaner has a massive centrifugal fan (massive relative to the CPU fan). What happens when you have a big fan spinning around? Yup, it creates a big electric charge. What happens when you put a big electric charge next to sensitive electronic equipment?
… Don’t use a vacuum cleaner to get rid of dust in a computer enclosure is all I’m saying …
A power strip (what you call a power bar, which isn’t wrong) is a terrible device to plug any sensitive electronics equipment into. They are generally poorly manufactured and can cause power spikes and brownouts several times a second.
If you buy a power strip for your desktop computer, make sure it has a UPS (uninterruptible power supply) built into it, which does two things: it levels out the charge over time (microseconds, but that’s the currency we deal in here), so that it delivers a consistent current to the device. Secondly, some of them come with a battery backup, which makes it quite heavy for its size, and this allows a safe shutdown in case of power loss. Many of them might even come with a USB cable which you plug into the computer, and when power is lost, it shuts down the computer for you. You find them at any good electronics store, or your local IT supplier.
Imagine someone who is not the remotest bit tech savvy trying to deal with computers at the best of times. When they work, they’re magic. When they fail, it’s like black magic to most people, and the wild thing is, THEY ARE RIGHT!