Helping people with computers... one answer at a time.
We're all told to shut down Windows before turning power off, but what if the power just goes out? If you're not protected, bad things can happen.
I am aware that not going through the proper Windows shutdown can possibly have negative effects on a computer. But my question is if a computer loses power (due to a household power outage, not anything wrong with the power supply), are these negative effects strictly software related (meaning a format and reinstall would fix them), or might it cause hardware problems as well?
Shutting down Windows properly before turning off the power to your computer is important. Not doing so can result in data loss and corruption as files are left only partially written to disk. But just turning off the switch is unlikely to actually harm your hardware.
Surprisingly, a household or other area-wide power outage turns out to be a completely different issue.
As I said, shutting down Windows properly before turning your computer off is important. Windows often keeps things in memory (RAM) that you really want to have written to disk, and shutting down Windows gives it the opportunity to flush all that information out to the hard drive. In addition, if you happen to turn off the power while Windows is writing something to the disk you run the risk of corrupting files; in the simplest case you may never notice. In the worst case your system might become unbootable.
In very rare cases I can think of scenarios where hardware might be damaged. What comes to mind are perhaps attached USB flash drives that also need the equivalent of a "safely remove hardware" on shutdown. If they don't get that, then perhaps a poorly designed device could be damaged.
But actual hardware damage from turning off the power switch at the wrong time is extremely rare. More commonly are data-related errors, which as you say can be resolved in the absolute worst case with a format and reinstall.
So why is household power loss different?
Well, to be fair, many times it's not. Power just ... goes out, as if someone threw a switch.
Unfortunately, all too many times it's nowhere near that clean.
A great example is a windstorm we suffered here in the Seattle area late last year. As trees fell onto power lines various things would happen:
Power would "blink" while the power grid automatically re-routed our power through other circuits, compensating for a supply line that had just broken.
Power would "brown out" as power lines began to short or fall onto trees and other structures where they made a partial connection. Brown outs are situations where voltage on the line falls levels much lower than the normal 120 volts we use here in the U.S..
Power would "surge" as power lines shorted with each other or fell onto other electrical equipment. A surge pushes the voltage above the normal 120 volts. Automated equipment is supposed to cut power when this happens, but the leading edge of the surge almost always makes it out to customers in some form.
After any of the above, power may finally go out. It may go out suddenly, it may brown-out and go away, or it may go away in a sudden surge followed by darkness.
I use trees and a windstorm as an example here, since in our area most of the power distribution network to homes and businesses is above ground due to the distances involved. Even areas with primarily underground power distribution are still at risk, though, since the primary high-voltage feeds that bring power into your area are still typically above ground. And of course there are certainly other situations besides windstorms that can cause power failures with all the symptoms that I've described above.
Losing power due to a power outage is typically not nearly as "clean" as just turning off a switch.
So consider your poor computer (or any electronic device) connected to the power that's browning out, surging, blinking out, and more before it finally goes dark.
Some equipment can handle that mess.
Some equipment cannot.
In fact, a lone power surge can certainly damage sensitive or just plain cheap equipment.
So, what do you do?
I have two recommendations, depending on how frequently you experience power problems in your location:
Surge Protectors Note that a "power strip" is not necessarily a surge protector. A power strip merely distributes power to multiple outlets, while a surge protector includes additional circuitry to automatically and cleanly turn off power in the case of a power surge.
Uninterruptible Power Supplies UPS's are usually large batteries with the appropriate circuitry to continue to provide backup power if the primary power source fails. A side effect is that they also typically include power "conditioning" which can eliminate temporary drops, surges and brownouts, and in the worse case will simply switch to battery backup if the incoming power becomes too unstable.
What you need depends on your situation. Sort of.
There's no reason not to use a surge protector. They're inexpensive insurance. All of your desktops, most printers, and other equipment should be connected to power though a surge protector.
If you experience frequent power problems, or if your computer is particularly sensitive or critical, then getting a UPS and connecting through that would make a lot of sense.
Laptops and equipment that use power "bricks" which convert from household voltage to something lower typically don't need any special treatment. Connecting through a surge protector doesn't hurt. Connecting a laptop which in a sense has its own form of "battery backup" through a UPS is somewhat pointless, and would add an unnecessary drain on the UPS's battery if the power went out.
In my case, my computers are connected through surge protectors, and only a subset of my networking equipment is connected to a UPS. My laptops, of course, will run on their internal batteries in case of a power failure. I simply make sure that the modem, router and wireless access point all have backup power from the UPS. This allows me to stay on-line for a few hours before the battery runs out.
Comments on this entry are closed.
If you have a question, start by using the search box up at the top of the page - there's a very good chance that your question has already been answered on Ask Leo!.
If you don't find your answer, head out to http://askleo.com/ask to ask your question.