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147. Nursing a sick computer

By Andrew D. Wright

What do you do when your computer starts shutting down suddenly on its own? Some folks give it to the kids and buy a new one. If that's not you, read on.

Sudden shutdowns can come from viruses, from memory errors, or from some hardware cause such as overheating.

Rule out the virus first. There are a number of different antivirus programs offering very good free versions. Download and install one if you don't have one already running. Make sure it's updated with the newest virus definitions before scanning your whole computer. Virus definitions are usually updated daily.

If you already have an antivirus program running, check the date on its definitions - if they are more than a day or two old, download new ones. Don't trust antivirus products more than a year or so old.

Errors in memory can be caused by exploding stars, or more accurately by the cosmic rays they produce. Constantly streaming through all of us all the time, if a high energy particle hits the right spot on a stick of computer memory, it can make the memory unusable.

To test memory, download Memtest 86+, a free utility. Burn the disk image to a blank CD then boot the computer from the Memtest CD. The tests will run automatically, writing and reading data to the different parts of your memory. If it goes through the entire run with no errors, you can rule out memory. If you find errors, replace the memory with a new stick.

If your computer is more than a couple of years old and particularly if you've had it sitting on the floor all that time, lint and dust may have built up inside it causing it to overheat. Computers don't take overheating well; they can start acting in bizarre ways or just flat out shut down.

Dust can be blown out with canned air. Fan blades on processor coolers can be cleaned - with the computer off - using dry cotton swabs. Twirl them on both sides of each fan blade while holding the fan from spinning with your finger. Don't blow fans with canned air since this can damage them by spinning them too fast. Don't use a household vacuum cleaner to clean dust out of a computer as this can create a damaging static electrical charge.

Another problem that can affect older computers is circuit fatigue from being powered on and off. When on, the computer produces heat and components expand. When turned off, these components cool and go back to normal size. Over time this can loosen connections, which can be fixed by simply re-seating the component. It can also loosen solder joints on printed circuit boards, which can be more of a problem to fix.

[Picture: Leaking capacitors] Unexpected shutdowns can also come from sub-standard components. Capacitors on the motherboard, the cylinder shaped things that look like little grain silos, can rupture and leak their electrolytic fluid. This is a particular problem with low cost computers made around 2002 and 2003. If you see some dried crud bulging out of the top or bottom of the capacitor, it's time for a new computer.

If the sudden shutdowns also come with the famous Blue Screen of Death, where the screen is all blue except for some white text, then there is probably some kind of software failure. Go to Windows Device Manager (Start - right click on My Computer - Properties - Hardware - Device Manager in Windows XP) and look for any yellow exclamation marks denoting unhappy hardware and reinstall its drivers or download new drivers.


Memtest 86+ (free):


Mousepad #60 - Spring cleaning your computer:


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Originally published 30 January 2009


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