Why do so many tech support solutions start with “reboot” or “turn it off”?

Quite often the first thing that a diagnostic technician will ask you to do is reboot your computer. Why? Because rebooting works surprisingly often.

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It seems like every time I call the tech support line for my software, operating system, or even my broadband connection, the first thing out of the technicians mouth is “reboot”. Or worse yet, “Turn the power off for a while.” What does that have to do anything? And why does it work?

It does seem like a bit of magic, doesn’t it? The computer’s acting up, you reboot it, and – poof – things are better again. At least for a while.

It gets even weirder when you achieve the same effect just by shutting it all down and pulling the power cord for a while.

A friend of mine provided a nice explanation for the power scenario, and I can speak a little bit to the magical mess that is software.

Jerrold Foutz is a friend of mine who’s an industry expert in the design of power supplies (Google “power supply design” and you’re likely to see his site in the top spot). He recently provided a very interesting write up on unplugging the power as perhaps the most effective electronics troubleshooting technique. The topic came up in a discussion some time back when I recommended power-cycling (unplugging, waiting 30 seconds, and then plugging back in) a router as a way to resolve a connectivity problem.

The fact is electronic components can sometimes get into an odd state, and as Jerry points out, power-cycling the equipment forces the equipment to reset and restart from a known good state.

The same is true for software.


Power-cycling the equipment forces the equipment to reset and restart from a known good state.

Complicated software (and what software isn’t these days?) touches lots of things on your computer as it runs. The longer it runs, the more it touches. Memory is used, released, and fragmented. Same for the disk as programs open, read, and write local and temporary files. And then there’s the hardware … video cards, network hardware, other peripherals – they’re all being accessed continuously. The result is that any of those (perhaps even all of them) can end up in states that can cause problems.

Naturally, it “shouldn’t” be that way, and the inherent quality of the software and/or hardware plays a role, but the bottom line is that it happens.

Hence, a reboot. It restores all the software to a known state.

And hence, a power-cycle. It restores all the hardware to a known state.

Healthy ComputerWell, a mostly known state. Temporary files, installed files, registry changes, and more will also remain. That’s why in some extreme cases, a reformat and reinstall can also be a recommended solution for some personal computers.

The router problem that started this discussion? Like many devices these days, it is actually a small single-purpose computer. It has internal memory that it uses to track various bits of information relating to the internet connections that traverse across it. And the longer it runs, the more likely that memory might have a problem. It could be hardware related, as explained in Jerry’s article, or something in its internal software, as I’ve outlined above. In any case, I typically have to reboot my router every couple of months.

 

There are 33 comments:

  1. lou bush Reply

    I retired a few year ago from a tv repair store. One of my most memorable puzzles was a tv that would work in my shop but not at the customers home. After two or three sessions at my store, the customer took the tv home and, on a whim, used a polarity checker on his ac outlet. Sure enough, the wiring was backward, neutral and hot were reversed. He corrected the wiring and it fixed his problem. He was kind enough to tell me about it. To this day, I dont understand how, with bridge circuits, reverse wiring could affect the power supply in the tv.
    But it did! Perhaps it could cause problems in computer products too.

  2. r taylor Reply

    when I was a boy tv reception sometimes would improve if I reversed the plug. this works on radio too. Todaymost appliances and plugs are polarized to prevent the mismatch of wires. but wrong connections can cause a degrarded signal. From an Electrician

  3. Leda March Reply

    Re: “reboot” or “turn it off”, how does “restart” differ from “reboot”?

    Restart typically means reboot.

    - Leo
    14-May-2009
  4. Yeppers Reply

    Leo, would you say a “turn-off” (where you use the Turn Off button, wait a few minutes while PC is shut down, and then power up again) is better than a mere “reboot” (where the actual shutdown period is very brief) in correcting some PC issues? Thanks.

    Yes. Turn off removes power from many of your computer’s components, putting them in a more definitive initial state. In worst case situations “pull the plug” is also included, because on some computers turning off doesn’t actually turn off absolutely everything.

    Leo
    07-Aug-2010

  5. Tom Evans Reply

    Read your article with interest, surely you must advice to “CLOSE DOWN” computer in the normal way first NOT just turn OFF and unplug. As I was advised always close down before you unplug computers.

  6. David Reply

    Yep. From the link: “Using the off/on switch or normal software shutdown will cure more than 90 percent of the problems, but not all of them. After turning off the computer, you need to pull the plug from the wall…”

    You can set the power button on most PCs (my experience through Win7; YMMV) to politely shut down the computer, so do that or the software shutdown, then pull the plug.

  7. DBA Steve Reply

    I’ve worked on mainframe computers for over 35 years and we are *not* in the habit of turning them off and then back on in order to make them work. That applies to the various IBM, SPERRY-UNIVAC, and RCA mainframes that I have worked on.

    Imagine, if you will, what chaos would ensue if real computers acted like this – banks, brokerage firms, governments would all just shut down until the re-boot was completed.

  8. Gary Reply

    Keep in mind that the PC’s power profile (under screen saver) has settings for what happens when you close a lid on a laptop. It also has settings for what happens when you press the power button. It may be set to sleep, hibernate or shutdown and if it is set to other than shutdown, you will not get the benefits of a restart or even a logoff (will not go back to a known state- the problem will still be there)

  9. Mike Castro Reply

    I work in the field of electronic security. One of the problems we encounter is induced power surges. Microprocessors and transistors are DC devices. These surges can and do shut down systems which dont have computers running them.

    When a lightning strike occurs the air is filled with static electricity which is why UPS systems exist for when you get a power fail or brown out. Very often power surges affect electronic devices and cause static or “hash”. This can be in the form of an AC surge. If the computers microprocessor detects such a surge it will shut down, ditto any device which has a microprocessor.

    As surges etc are momentary occurances removing the power makes the problem go away, the device will in effect forget the problem and restart. There’s no memory of ther problem in ther CPU etc so it starts up again. Thats why a restart as opposed to a shutdown and reboot are different. The problem could still be present.

    Surges or induced AC can be simply caused by having a mains power power cord tied up with a VGA cable or a mouse cable. The AC field around a 230vac mains cable can be anything up to 1 metre ( 3 feet in old money ) around the cable in any direction.

    Surges and spikes can occur simply by switching on a light or another electrical device. Computers being the little darlings that they are have many devices which can “hang” in the same way as if they had be hit by a surge or spike.

    So restarting from “cold” i.e. power down and restart is very often the only way to clear the problem. The big concern of course is that it actaully hasnt fixed the problem, just merely ignored it for the time being. It will happen again.

    Whatever you do don’t bundle mains cables with periferall ones, keep them apart and never coil cables, you are just making a large electric coil.

    Keep it clean and tidy !!

  10. Gaudwin Reply

    Yesterday I had a problem with my NEXTBOX (Cable TV): The screen went blank; couldn’t put the power off from the remote or the power button on the box. I unplug my it and reconnected it. It reboot itself; and everything was find.

  11. Glen Reply

    i have my PC tower, printer, TV and cable box all hooked up to a surge protector power strip which is plugged into an outlet connected to a wall switch. every night i turn off the wall switch. according to this article i`m doing a good thing. am i right?

  12. Ken R Reply

    Just to confirm Mike’s comments, while clicking ‘Restart’ does re-boot the computer, you should ‘Shutdown’ and wait e.g. 30 secs before re-starting to properly clear memory.

    Does the advice to ‘remove the power cord’ mean that some parts of the machine are still powered even when turned off?

  13. Bob D Reply

    And of course there is the opposite issue.
    I shut down, turned off power supply, and unplugged.
    Then opened the desktop’s case, and noticed almost no dust. I blew some air around with a vacuum cleaner, anyway.
    Closed the case, repowered, and restarted.
    No ethernet.
    Restarted again, and ethernet returned.
    Maybe humidity was too low, and static hit the ethernet circuitry.

  14. Mobile PC Medic Reply

    This is one of the best reasons to just get in the habit of turning your computer off when you’re done working for the day.
    Why wait for trouble to happen?
    Many a self inflicted computer problem has been caused by people troubleshooting problems that could have been easily solved with a reboot.

  15. Texas Mike Reply

    R Taylor: Yes, sadly there is no shortage of LICENSED electricians who do, indeed, fail to properly follow NEMA polarity for wiring installations. I’ve encountered that so much and for my own onsite work, I’ve had to carry my own self-made adaptors to overcome those mistakes.

    Which leads me to Lou Bush’s comment about why it can still affect equipment, even with isolation transformers, bridge rectifiers, AND forced ground. You already know that simple 120v AC is not necessarily 0v at neutral, and 120v at maximum. It could “float” from 5v neutral to 125v maximum and still be 120v AC. Because of that potential shock hazard, equipment today must be force grounded at neutral. That solves the shock hazard, but if there is still a long distance for the true ground, audio and video can still pick up a “ground wave” from a wiring reversal and be introduced into the equipment by the chassis ground, bypassing the transformer and bridge circuit. In fact, lifting the ground will often remove the problem, although it does violate the safety aspect.

  16. Frank K. Reply

    @Ken R. …yes the power cord must be detached from most desktops in order to completely remove all power usage. My PC has 3 USB ports that stay hot even after I have turned the PC off.
    Unplugging your power cord for a minute or two allows the residual power to drain from the system.

  17. Hew Helps Reply

    And for a laptop, you need to disconnect the battery. Even more important really since any users just put the laptop into sleep mode! It will be interesting to see how Windows 8 copes with more sleep and less shutdown !

  18. Sean Reply

    I get a good number of systems that come that have a power issue and when power cable is disconnected for a while the system boots clean and works ok for a time.
    I find this to be caused by generic or cheap build PSU’s. I put it down to dirty voltage and these cheaper PSU’s cannot feed clean stable voltage to the components.
    When ever I build a new system or replace a failed or faulty PSU I always install a good quality one.
    They might be more expensive but are much better in the long run as they deliver clean stable voltage to the components so you get better performance and longevity from the system overall.
    I also suggest for folks who use the PC a lot or for work to invest in a UPS with surge protection.

  19. snert Reply

    I turn off my power strips to all my computing equipment at last once a week for an hour or more. If I’m having glitches anytime the first thing I do is power off and reboot. 95% of the time that takes care of it.

  20. Mark J Reply

    @Ken R
    There are sometimes parts of the machine receiving power when the machine is off and it’s still plugged in.This is often visible in the form of LEDs that remain lit when the power is turned off. One example is a standby function which allows a device to power up faster.

  21. Alex Dow Reply

    The very fact that most varieties of PCs have “SOFT” switches points to there being degrees of residual power present, when apparently switched “OFF”.

    Take my Tower PC, after connecting mains to it, I simply press the built-in SOFT Switch to BOOT it.

    However, unlike a lamp or similar, I do not press that “SOFT” Switch when allegedly “switching OFF”.

    I simply select “Power Down” or similar; and never touch that SOFT Switch at any point.

    So there must still be power somewhere on the PC, as pressing that SOFT Switch restarts it.

    It is more complex if one has to press and hold-down that switch, when the PC will not shut-down conventionally.

    But all those variants do point to having to unplug the power cable and/or switching off “at the wall”, to completely remove the power from a PC; and in the case of Laptops etc, the battery has to be disconnected, as others have stated.

  22. Tony M. Reply

    Yes, ditto this advice from Leo. There are so many little things that could have gotten “out of kilter,” you may as well begin your diagnostic/repair procedures with a reboot and/or a power cycle.

    I learned this the hard way once as Windows simply would not start. I rebooted several times and eventually even restored all my Windows-related directories, but to no avail.

    Frustrated, tired, and wondering what to do next, I gave the whole thing a break, meaning I just shutdown the system and stepped away for a while. A short time later, although I had no new ideas other than possibly re-installing the OS, to my tremendous surprise and relief, Windows simply started right up as if nothing had ever happened, and I never experienced that elusive problem again.

    So, what I learned from this: Particularly since a cold start (power cycle) is so easy to do, if a simple reboot doesn’t do the trick, then consider cycling the power. Even if it doesn’t work, since it takes just a few moments, you might as well try it.

  23. Barry0714 Reply

    One additional note to the comments above. Sometimes a reboot is needed when the system has downloaded loaded and partially installed an upgrade package. Many have systems set this function to auto and forget that our computers are doing things in the background.

  24. KRS Reply

    I’ve been told to shut down, disconnect the power cord and press the Start button, which discharges capacitors and flushes persistent caches. When I disconnect and press Start, I notice a tiny blip of lights, which means that something is still charged up.

    I have no idea whether this works, but it’s easy and Cuddnt Hoit.

  25. Geldhart Reply

    As a technician, I’m trained to start with the simplest possible solution first. Faced with the prospect of reinstalling Windows from scratch, having to back up all the data, and get all the icons “just right” for some of my very very picky clients, I will have them turn off the computer. A common technique to ensure this happens is to have them check that the “power cables aren’t loose”. Turn off the computer properly, unplug the power from the wall, blow on the prongs to remove any loose dust that might have gotten on it, then plug it back in”. Is it working now? Great. Call me back if it happens again.

  26. Craig Reply

    Glen said:
    “i have my PC tower, printer, TV and cable box all hooked up to a surge protector power strip which is plugged into an outlet connected to a wall switch. every night i turn off the wall switch. according to this article i`m doing a good thing. am i right?”
    I do likewise at home and work with no ill effects. I am an electronic technologist for 3 decades.

  27. John Reply

    I have had two different laptops (a Toshiba and a Dell) become “unbootable”. Nothing seemed to get them to turn on.

    In both cases the solution was to remove the power cord and battery for a couple of minutes, then press and hold down the power/start button for 15 seconds or so, then reassemble and start up again. It worked.

  28. Don N Reply

    Here at work we have a SCADA (supervisory control and data acquisition system). Periodically the two servers on the system will hang and stop working and the only solution is to reboot them. I’ve been told by my IT support that “servers” should not have to be rebooted. Do “servers” have the same hang-up problems as computers and require the periodic “reboot”?

  29. Jerry Evans Reply

    About the time he went on sabbatical, Leo posted an article explaining that servers are nothing but computers dedicated to a specific task. You could probably do a search on Ask Leo to find the article.

    Servers are subject to the same type of hang-up problems as any other computer. How often they may need to be rebooted depends on factors such as their purpose, usage, and what programs they run.

  30. Tony Reply

    Strange enough I have a workmate who never switches off his laptop. For me, if I take mine from work to home, or from home to work, without switching it off completely, I get problems which can only be solved by shutting down and starting again.

  31. Michael Reply

    This applied to my Internet/clock radio which out of the blue would not recognize that it was plugged into an electric outlet. It fell back to the internal battery and after a period of inactivity the battery shuts the thing down. Long story short, all it needed was to be rebooted.

  32. Mat Lambor Reply

    I have a virus/malware called Phython27.DLL I’ve seen it comes with Uniblue\SpeedUpMyPC\ I’ve been on google which has answers plus downloads which i’ve carefully selected but i’ve tried them all, (system restore the lot). Nothing has worked and to make it worse it’s knocked out my firewall/Windows Deafender and as above systems restore along with Windows Updates email settings you name it. Any help would be very wellcome.

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