Tech Blog

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When you first turn on your computer you’re probably greeted by a beep so familiar that you’ve stopped noticing it, just dismissing it as the sound of a computer turning on and nothing more. This isn’t just a random beep though. It's part of your computers Power-On Self-Test (POST), a set of diagnostics your computer performs to make sure everything is set for it to run. This can tell you a lot about your computer and help you diagnose problems.

Generally if there is a major problem detected by the tests in your computer’s hardware you are notified with a distinct audio beep or an error message displayed on your monitor. The beeps are often enough to help you diagnose the problem depending on what noises you’re hearing. All the tests are handled by your computer’s BIOS (Build In Output System) before your operating system (ie Windows, or OSX) even begin starting up.

Generally when you’re listening to your computer’s power-on beeps you should listen to the pattern and length of the beeps. The normal notification is the one short beep signifying all is well. If it differs from that you’ve got a problem. Think of the beeps as your computer trying to talk to you like Artoo-D2. The language it uses can occasionally vary from computer to computer but in general they don’t often deviate all too much. Consult your computer or motherboard’s manual for more information on what exactly the codes indicate for your particular hardware.

Most users will never hear anything but the familiar one-beep hello from their computer but if you tweak or upgrade your system, or especially if you build a new computer from scratch, you’ll do well to listen for these beeps. I built a computer just last week which wouldn’t start up initially. After listening to the POST beeps I was able to tell that there was a problem with the RAM. After a few seconds of fiddling I had it up and running without having to guess and investigate at what the problem could be.  Without POST, the problem could have been anything.