Midweek Musing: Have you turned it off and on again?

I love the IT Crowd, which was on Channel 4 some years ago (and is still on All 4 to watch now if you want). One of the most famous lines in the show is “Hello I.T. Have you turned it off and on again?”.
I want to take a little time to take it apart, discuss the myth and the reality of what is actually happening when someone says “Turn it off and back on again”. And even the more advanced “Turn it off, turn off the power, then wait 30 seconds and turn it back on”.

The Myth

It is a common misconception that this is the work of lazy IT folk who just want an easy answer. In the IT crowd this is defiantly the case (they even built an answering machine to do this job for them) which does not help the situation… Some people also believe that it actually has no powers at all! In a previous job I even had people tell me that they turned the computer off but actually they didn’t do it.

The Reality

This totally depends on the device, but most devices have tiny computers and processors inside them, for example your TV has a computer which manages the menu and TV guide system. These computers run an operating system of some description, much like Windows for your PC, Android on your tablet or even a version of Linux you might have in your car (my car has a tape player – not so much anything too clever going on there, but still…)
When you turn it off and take the power out you are basically shutting it off and making it “forget” anything which is stored in RAM (Random Access Memory). This memory is used to help process requests, in the TV example it might process commands sent by the remote control.
When you turn the device back on again it forces the Operating System to start up from the beginning. This is the same as when you turn your PC on and you see the Windows loading screen. By starting it from the beginning it means it has a chance to recover from anything which may have gone wrong.
But what about taking the power out Mike? Good question… some devices don’t actually shut down when you tell them to, chances are you turn your TV off and there is still a red light on, or maybe it looks like it has turned off but actually it is still running behind the scenes. By taking the power out (or removing the battery) you are making sure that it is really off. Waiting 30 seconds means that anything inside which might still be getting small amounts of power has time to fully turn off. One article I read while researching this said “I’m an electrical mechanic and I’m always surprised when all I have to do to fix a multi-million dollar piece of equipment is turn it off and back on.”
Hopefully this explains a little more about what is happening behind the scenes when something is turned off and back on again. As ever if you have any questions, comments or good turned it off and on again stories? Don’t hesitate to leave a note in The Clubroom or in the comments section below.
The short version: “It resets the system to a known, good initial state.”
I will leave you with a scene from the I.T Crowd…

Happy Weekend
Mike =)