Pulling the plug out for 10 seconds

power supply

When calling support the other day he told me to reset my DSL modem by pulling out the power, leave it out for 10 seconds, and then plug it back in. This is something I have heard many times with different kinds of equipment. I have also heard it in relation to computers. That when you turn it off, you should wait at least 10 seconds before you turn it on again.

  • Why not just plug it in again right away?
  • Why 10 seconds, instead of, say… 3 or 30?
  • Should you really, always do this; just with certain types of equipment; just in certain circumstances; or is it just a "myth" thing that people have said so often that they believe it to be fact?

Best Answer

A lot of modern technology contains capacitors! These are like energy buckets, little batteries that fill up when you put a current through them, and discharge otherwise. 10 seconds is the time it takes most capacitors to discharge enough for the electronics they're powering to stop working. That's why when you turn your PC off at the wall, things like an LED on your motherboard take a few seconds to disappear. You probably could wait a different time, but 10 seconds is the shortest time you can be sure everything's discharged.

Related Question