No Comments Written by Robert on July 28, 2008 – 2:46 pm

Nearly all current laptop computers with built-in WiFi circuitry have a physical switch that you must turn on to energize the transmitter/ receiver. (The switch is there to help conserve battery power when the WiFi system isn’t needed, and also to comply with requirements by airlines and some high-security offices that there be no unauthorized radio equipment in use.)

Consult your laptop’s instruction manual or call the support desk to find the switch; better machines may add a tiny LED indicator that glows when power is on. Note that some machines may enable or disable the circuitry with a soft switch within a utility program. The other common cause for WiFi problems is the lack of an acceptable signal or a blocked signal.

Certain types of objects, including metal screens or particular types of building construction, block signals. And the fact is that some laptops have better antennae or better receivers; I’ve been in situations where the guy next to me can pick up a strong signal, while I get nothing. Sometimes the solution is to rotate the laptop or move to a new location.

Wired hardware

A damaged or improperly attached Ethernet cable at the laptop or router end may be the culprit. Try substituting a known-good replacement cable.

Problems with the network interface card (NIC) may be the cause, too. If you’re using an external adapter that connects to the laptop’s USB port or PC Card slot, make sure it’s properly plugged in. External devices usually have LED lights that indicate a proper connection; consult the instruction manual for the device to determine their precise meaning.

You can check on the status of a built-in NIC:

1. Go to the Windows Control Panel and double-click the System icon.

2. Choose the Hardware tab and then click the Device Manager button.

3. Expand the Network Adapters item, then double-click the listed hardware.

You see a hardware report in the Device status window. If you want to continue searching for a hardware problem, click the Troubleshoot button and follow the instructions given by Windows.

Wireless software

Nearly all laptop manufacturers add special utility programs to the Control Panel to set up and manage the WiFi circuitry. A typical wireless link utility includes a Hardware tab that includes a report on the device status, properties, and a Troubleshoot button.

Unexplained slowdown and strange Internet behavior

You just might have a system that’s clogged up with adware and spyware, which are unwanted snippets of programs that report on your Internet comings and goings to outsiders. Although the makers of these programs may claim that their products are benign (they’ll say they help deliver customized content to you when you visit the home pages of advertisers), many users feel otherwise. At best, they’re an intrusion, and at worst they may deliver confidential information to thieves. And whether they’re “good” or “bad,” nearly all of them steal some of your computer’s speed as they build up on the disk.

You can use the facilities of a capable system utility, such as Norton SystemWorks (at www.symantec.com), to scour your Internet browser to remove cookies (records of visits and sign-ons) and other notations placed by advertisers. Even better are specialized cleaners such as Ad-Aware, which you can find in a free version (as well as a more capable commercial version) at www.lavasoft.com. Clean your system at least once a month, and more often if you spend most of your time online.

No video

Short and simple: Have you managed to shut off the LCD screen and redirect video output to the VGA or S-Video output for an external monitor or television? Most laptops have a key combination that lets you use the LCD only, the LCD and an external monitor, or (and this one could be the problem) the external monitor only. Consult the machine’s manual or study the keyboard itself to determine the keys; on some machines it’s the Fn+F5 combination. One other possibility is that your system BIOS has somehow been changed, perhaps as the result of an electrical shock, a system crash, or a virus. Check the instruction manual for the key to press during bootup to display the BIOS, and then look for the entry that refers to video output; it should say LCD.

Defects onscreen

Laptops have two types of screen problems: those you can learn to live with, and those that require you to ship the machine to a repair shop for what may be costly surgery.

One or more thin, black or white, horizontal or vertical lines that run across the screen indicate developing problems with the LCD electronics. Usually this can be repaired for about $100 to $200, depending on the model. However, the image or text may still be readable and some users are willing to put up with the problem, which may never get worse.

A more serious problem is a dim or discolored display, which a technician has to deal with. And, of course, a completely dead screen has to be repaired.

You can, though, work around a failed screen by attaching an external computer monitor to the VGA output, or by using an S-Video or composite video output to a television set. (Consult your instruction manual for the keyboard combination to enable the external video output.)

If your laptop can deliver an image to an external monitor, you can continue using it that way although it’s a bit problematic to lug a 36″ Sony onto an airline seatback tray. But the mere fact that you can see an image on an external device is one way to determine if the problem is isolated to the screen or if it’s a more complex, expensive problem caused by a motherboard or video circuitry failure.

No sound of music

Two common problems cause a sudden end to music, system alerts, and other essential noises: The hardware volume wheel has rotated to 0 or the software volume control has been muted. The unfortunate thing is that both of these problems can sneak up on you unexpectedly.

On most laptops, the rotary volume control for built-in speakers is on the side of the machine; you can very easily move it one way or another as you slide your laptop into a carrying case. And for reasons that neither Microsoft nor any other support desk has ever adequately explained to me, the Windows volume control’s mute buttons can easily be enabled accidentally in the course of ordinary computing. The same problem can also afflict a third-party software volume control associated with a separate sound card.