Any Old Port In A Back Panel: Hooking Up A Computer

Computers may have created a new definition of the word “cursor” for users, but they’re not hard to properly hook up. Almost all the ports are different, so it’s physically impossible to screw things up too badly, at least without using power tools. Like any other rule, there are a few exceptions.

  • The only thing that’s safe to plug and unplug with the power on is a USB device. If you start swapping anything else around with the system running, you’re asking for trouble.
  • The keyboard and mouse can be interchanged accidentally (if you’re using the ones with round connectors instead of USB). Neither will work, but no damage will be done. Most computer manufacturers color code their mouse ports green and keyboard ports purple.
  • It’s possible to mix up the audio jacks. Most computers have a green audio jack (speakers go here), blue (line in – you would use this to get sound into the computer from, say, a stereo or portable player), and pink (microphone for getting live sound into the computer; will not interchange with line in. Often has a picture of a microphone). Some high end computers will have more audio ports, usually for Dolbytm 5.1 sound.
  • Most computers have a network port. This looks like an oversize phone jack with a little picture of 3 computers linked by lines. It is possible to plug a phone cord into this jack without damage, but you won’t get any action out of your dial-up modem if you do. The (dial-up) modem jack (if present) is in a separate location from most of the other ports. (You also can’t use a phone cord to hook up the computer to your broadband modem.)
  • If your dial-up modem has two phone jacks on it, they are not interchangeable either. The phone cord must be plugged into the jack labeled line (sometimes with a little picture of a phone jack). The other jack, labeled phone (often with a picture of a phone) is for plugging in an extension phone or fax.
  • The monitor port (15 holes in a D-shaped shell, with a little picture of a monitor) and the serial port (9 pins in a similar D-shaped shell, with a picture of ones and zeros) look somewhat alike, but one cannot be plugged into the other. If you can’t get your monitor cable to plug in, look for another port elsewhere.
  • Whenever plugging in something like a monitor cable that has screws, just finger tighten the screws. They are only there to keep the cable from falling off.
  • Some late model computers have HDMI or DVI monitor jacks. These must be used with the appropriate monitor.
  • Many different peripherals use USB ports. You’ll find several of these on most computers. Flash drives, removable drives, USB hubs, USB keyboards, and USB mice require no software installation; the first time you plug it in, the computer will find and install the correct driver. You’ll see dialog boxes or balloons telling you it’s doing this; give it some time to finish before you start trying to use the device.
  • When installing a new USB device other than those listed above, always install the software before plugging the device in for the first time, unless the instruction manual specifically tells you otherwise.
  • There are extension cables available for most computer ports but you should only use them when absolutely necessary. Longer cables give less reliable data transfer. Rule of thumb for maximum total length: USB cables, 10 feet; serial cables, 25 feet; keyboard and mouse, 10 feet; network (Category 5), 300 feet; monitor cable, 15 feet. If something doesn’t work reliably or at all, try plugging it in with the shortest cable you can find and see if operation improves.
  • Don’t forget to plug in the power cord, too!
Typical computer back panel.

Typical computer back panel.

Typical computer back panel ports. Your computer may have more or fewer ports, and in different positions; These are the most common. Power and modem connections not shown.

  1. Keyboard (Purple)
  2. Mouse (Green)
  3. Serial port. Mostly replaced by USB, still used occasionally for dial-up external modems, GPS units, and other low speed devices. Note the 9 pins instead of holes.
  4. Parallel port. Also mostly replaced by USB. Often used for printers and scanners. Sometimes colored pink.
  5. VGA Monitor port. Still the most common monitor port. Note the difference between this and the Serial port. Often colored blue.
  6. USB Ports. Used for almost everything – Printers, mice, keyboards, cameras, and others. Most computers have several, front and back.
  7. Network Port. Note it is wider than a phone jack, although it resembles one. The Modem jack(s) (Not Shown) are usually in a separate location on the back panel.
  8. Audio Jacks. Accept standard 1/8” headphone, speaker, and microphone plugs. Often colored pink (Microphone), green (Line out/Speakers), and blue (Line in).

This post has been adapted from my new book, “Deciphering the 21st Century,” Available now! Click here to read all about it.

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