System Maintenance and Assembly

This chapter is from the book

Upgrading and Repairing Laptops

Learn More Buy

This chapter is from the book

This chapter is from the book 

Upgrading and Repairing Laptops

Learn More Buy

Preventive Maintenance

Preventive maintenance is the key to obtaining years of trouble-free service from your computer. Laptop systems are especially prone to problems because they are portable and therefore exposed to more problems than desktop systems, which remain in a single location. All it takes is an accident such as dropping the system onto a hard surface to turn thousands of dollars worth of computer into so much junk. A little care combined with some simple preventive maintenance procedures can reduce problem behavior, data loss, and component failure as well as ensure a longer, trouble-free life for your system. In some cases, I have "repaired" ailing systems with nothing more than a preventive maintenance session. Preventive maintenance also can increase your system's resale value because it will look and run better.

Developing a preventive maintenance program is important to everyone who uses or manages laptops. The two types of preventive maintenance procedures are passive and active.

Passive preventive maintenance includes steps you can take to protect a system from the environment, such as using power-protection devices; ensuring a clean, temperature-controlled environment; and preventing excessive vibration. In other words, passive preventive maintenance means treating your system well.

An active preventive maintenance program includes procedures that promote a longer, trouble-free life for your laptop. This type of preventive maintenance primarily involves the periodic cleaning of the system and its components. The following sections describe both passive and active preventive maintenance procedures.

Passive Preventive Maintenance Procedures

Passive preventive maintenance involves taking care of the system by providing the best possible environment—both physical and electrical—for the system. Physical concerns include conditions such as ambient temperature, thermal stress from power cycling, dust and smoke contamination, and disturbances such as shock and vibration. Electrical concerns include items such as static electricity, power-line noise (when the system is plugged into a wall outlet or other external power source), and radio-frequency interference. Each of these environmental concerns is discussed in the following subsections.

General System Care and Handling

Laptop computers are expensive machines built with significantly tighter tolerances than their desktop counterparts. Although most laptops are designed to function reliably in normal environments, it helps to use some common sense when transporting, operating, or otherwise handling a system. If you treat the system as if it were a very expensive piece of precision electronic machinery (which it truly is!), you will greatly minimize the chances of problems occurring.

Instead of telling you what you should do to take care of your system, it is perhaps easier to tell you what you shouldn't do. I often observe people doing things to their laptop computers that make me cringe. Here is a list of bad things you should not do to your laptop computer:

• Drop, bump, or physically punish the system, especially while it is running.

• Drop the system. Even if it is in a carrying case, many cases are not padded well enough for rough treatment.

• Pack a laptop in luggage that will be checked at the airport, thus subjecting it to very rough handling.

• Place heavy cases or other objects on top of a laptop (such as in the overhead compartment on a plane), even if it is in a carrying case.

• Store the system where the temperature is below 41°F (5°C) or above 95°F (35° C).

• Operate the computer on a blanket or other soft surface where material might bunch up and cover the cooling vents on the sides or back, which will cause the system to overheat.

• Operate the computer while it is still half-inside a carrying case, which will block the cooling vents and cause overheating.

• Place the system closer than about 5 inches (13cm) from any electrical device that generates a strong magnetic field, such as electric motors, TVs, refrigerators, and large audio speakers.

• Operate two-way radio transmitters in close proximity to the system, which can induce currents and voltages causing lockups or failures.

• Spill liquids on the system, which may contaminate the internal components and/or cause a short circuit.

• Place heavy objects on the system with the lid closed, or pack the system in a tightly compressed suitcase or bag, which may put excessive pressure on the LCD display.

• Place an object between the display lid and keyboard, which may cause damage when the lid is closed.

• Pick up or hold the system by the LCD display, which may damage the display and/or the hinges.

• Scratch, twist, or push on the surface of the LCD display.

• Move the system or pull on the AC adapter cord while the adapter is plugged in, which may cause the plug to break off and/or damage the socket.

• Plug a modem cable into an Ethernet port (and vice versa), which may damage the connectors.

• Hard-mount the system in a vehicle or anywhere that it is subject to strong vibration.

• Crush, drop, or press on the cover of a disk drive while it is removed from the system.

• Insert a floppy disk into a floppy drive at an angle or upside down, which may cause it to jam in the drive.

• Place more than one label on a floppy disk, which might cause it to jam in the drive.

• Touch the lens on the CD-ROM tray, which may contaminate the lens and/or throw it out of alignment.

• Connect the internal modem in the system to a PBX (private branch exchange) or other digital telephone line that may subject the modem to improper voltages, thus causing permanent damage.

• Forget your passwords. If you forget a Supervisor or hard disk password, there is no easy way to reset it, and you may have to replace your motherboard or hard disk.

The systems you use will last a lot longer if you avoid any of the aforementioned behavior.

The Operating Environment

Oddly enough, one of the most overlooked aspects of preventive maintenance is protecting the hardware—and the sizable financial investment it represents—from environmental abuse. Computers are relatively forgiving, and they are generally safe in an environment that is comfortable for people. Portable computers, however, are often tossed around and treated with no more respect than a cheap calculator. The result of this type of abuse is often numerous system failures.

Temperature, Humidity, and Altitude

All computers are designed to operate within specific ranges of temperature, humidity, and altitude. Exceeding the allowable ranges places stress on the system and can cause it to fail prematurely. Therefore, keeping an eye on the conditions where you both use and store your computer is important for the successful operation of the system.

Temperature, humidity, and altitude variations can lead to serious problems. If extreme variations occur over a short period, expansion and contraction can cause signal traces on circuit boards to crack and separate, and solder joints can break. Extreme humidity can cause contacts in the system to undergo accelerated corrosion or condensation to form in the system and disk drives. Extremely dry conditions can cause problems with static electricity. Operating at high altitudes causes problems with cooling (lower density air renders the cooling system less effective) as well as the internal "air bearing" on which the heads float in the drive while operating.

To ensure that your system will be operated in the temperature, humidity, and altitude ranges for which it was designed, I recommend you consult your system specifications for the environmental range limits. Most manufacturers provide data about the correct operating temperature range for their systems in the owner's manual. Two sets of specifications are normally listed—one that applies to an operating system, and the other for a system powered off. As an example, IBM indicates the following allowable environmental limits for most of its ThinkPad portable systems:

Maximum altitude without pressurization 10,000 ft. (3,048m)

Temperature range (not operating) 41°–110°F (5°–43°C)

Maximum temperature while operating

Above 8,000 ft. (2,438m) 88°F (31°C)

Below 8,000 ft. (2,438m) 95°F (35°C)

Minimum temperature while operating

Not using the floppy drive 41°F (5°C)

Using the floppy drive 50°F (10°C)

Minimum battery temperature when charging 50°F (10°C)

Relative humidity while operating

Not using the floppy drive 8%–95%

Using the floppy drive 8%–80%

Note that the maximum allowable ambient temperature drops to only 88°F (31°C) at altitudes over 8,000 ft. (2,438m). This is due to the lower air density at high altitudes, which reduces the efficiency of the computer's cooling system. Also note the minimum operating and nonoperating temperature of 41°F (5°C). This means that for many areas of the country, it may not be wise to leave a laptop system in a car for more than a short period or to ship a system using a mail or package carrier during the winter. As you can see from the table, most environmental conditions that are comfortable for people are also good for laptop computer use.

Temperature Acclimation

In addition to the temperature limits just discussed, it is a good idea to avoid rapid changes in temperature as well. If a rapid rise in temperature occurs—for example, when a system is shipped during the winter and then brought indoors—you should allow the system (and the hard drive inside) to acclimate to normal room temperature before turning it on. In extreme cases, condensation can form on the platters inside the drive's head-disk assembly (HDA), which is disastrous for the drive if you turn it on before the condensation has a chance to evaporate.

Most hard drives have a filtered port that bleeds air into and out of the had (hard drive assembly) so that moisture can enter the drive; therefore, after some period of time, it must be assumed that the humidity inside any hard disk is similar to the humidity outside the drive. Humidity can become a serious problem if it is allowed to condense—and especially if you power up the drive while this condensation is present. Most hard disk manufacturers have specified procedures for acclimating a hard drive to a new environment with different temperature and humidity ranges, especially for bringing a drive into a warmer environment in which condensation can form. This situation should be of special concern to users of laptop and portable systems. If you leave a portable system in an automobile trunk during the winter, for example, it could be catastrophic to bring the machine inside and power it up without allowing it time to acclimate to the temperature indoors.

The following text, along with Table 3.1, are taken from the factory packaging that Control Data Corporation (later Imprimis, and eventually Seagate) used to ship with its hard drives:

If you have just received or removed this unit from a climate with temperatures at or below 50°F (10°C), do not open this container until the following conditions are met; otherwise, condensation could occur and damage to the device and/or media may result. Place this package in the operating environment for the time duration according to the temperature chart.

Table 3.1 Hard Disk Drive Environmental Acclimation Table

As you can see from this table, you must place a portable system with a hard drive that has been stored in a colder-than-normal environment into its normal operating environment for a specified amount of time to allow it to acclimate before you power it on. Manufacturers normally advise that you leave the system in its packing or carrying case until it is acclimated. Removing the system from a shipping carton when extremely cold increases the likelihood of condensation forming.

Of course, condensation can also affect other parts of the computer, especially circuit boards and connectors, causing short circuits or corrosion that can negatively affect operation or even cause damage.

Static Electricity

Static electricity or electrostatic discharge (ESD) can cause numerous problems within a system. The problems usually appear during the winter months when humidity is low or in extremely dry climates where the humidity is low year-round. In these cases, you might need to take special precautions to ensure that your computer is not damaged. See the section, "ESD Protection Tools," in this chapter for more information on ESD.

Static discharges outside a system-unit chassis are rarely a source of permanent problems within the system. Usually, the worst possible effect of a static discharge to the case, keyboard, or even a location near the computer is a system lockup, which can result in lost data. If you know you are carrying a charge, before touching the keyboard or system you might try discharging yourself by touching some other metal object or device to bleed off some of the charge. Whenever you open a system unit or handle devices removed from the system, you must be more careful with static.

Radio-Frequency Interference

Radio-frequency interference (RFI) is easily overlooked as a problem factor. The interference is caused by any source of radio transmissions near a computer system. Living next door to a 50,000-watt commercial radio station is one sure way to get RFI problems, but less-powerful portable transmitters can cause problems, too. I know of many instances in which cordless telephones have caused sporadic random keystrokes to appear, as though an invisible entity were typing on the keyboard. I also have seen strong RFI from portable two-way radios cause a system to lock up. Solutions to RFI problems are more difficult to state because every case must be handled differently. Sometimes, simply moving the system eliminates the problem because radio signals can be directional in nature. If you have external devices attached to your laptop (such as an external mouse or display), sometimes you must invest in specially shielded cables for these devices.

One type of solution to an RFI noise problem with cables is to pass the cable through a toroidal iron core, a doughnut-shaped piece of iron placed around a cable to suppress both the reception and transmission of electromagnetic interference (EMI). You'll notice these cores on many of the laptop external data (USB, FireWire, and so on) and power cords. If you can isolate an RFI noise problem in a particular cable, you often can solve the problem by passing the cable through a toroidal core. Because the cable must pass through the center hole of the core, it often is difficult to add a toroid to a cable that already has end connectors installed.

Radio Shack and other electronics supply stores sell special snap-together toroids designed specifically to be added to cables already in use. These look like a small cylinder that has been sliced in half. You simply lay the cable in the center of one of the halves, and snap the two halves together over the cable. This type of construction makes adding the noise-suppression features of a toroid to virtually any existing cable easy.

The best, if not the easiest, way to eliminate an RFI problem is to correct it at the source. It is unlikely that you'll be able to convince the commercial radio station near your office to shut down, but if you are dealing with a small radio transmitter that is generating RFI, sometimes you can add a filter to the transmitter that suppresses spurious emissions. Unfortunately, problems sometimes persist until the transmitter is either switched off or moved some distance away from the affected computer.

Dust and Pollutants

It should be obvious that dirt, smoke, dust, and other pollutants are bad for your system. The cooling fan found in most modern laptop systems carries airborne particles through the system, where they can collect inside. I'm not saying that it is unsafe to use a laptop system outside, or in an environment that isn't absolutely pristine, but I am saying that you should consider the working environment. If you take care of your system, it will serve you longer and with fewer problems.

If your system is going to be regularly used in an extreme working environment, you might want to investigate some of the specialized systems on the market specifically designed for use in harsh environments. Panasonic, for example, manufactures a complete line of systems called Toughbooks, which are specially designed to survive under harsh conditions. Durability features available in the Toughbook line include the following:

• Magnesium alloy case with handle

• Moisture- and dust-resistant LCD, keyboard, and touchpad

• Sealed port and connector covers

• Shock-mounted removable HDD in a stainless-steel case

• Vibration- and drop-shock-resistant design

• Rugged hinges

Unfortunately, in most cases, because rugged systems must be specially designed, and especially because they don't sell as well as the mainstream, nonrugged models, rugged systems are usually more limited in options, are not updated as frequently as mainstream models, and in general will offer much less performance than mainstream models. Still, if a mainstream model simply won't do for durability, you should consider one of the specially designed rugged models, such as the Panasonic Toughbooks. For more information on the Toughbook line of laptop systems, visit Panasonic at http://www.panasonic.com/toughbook.

Tips for Transporting Your System

When transporting a laptop computer, I recommend you consider the following guidelines in order to protect the system:

• Remove all floppy disk and/or CD/DVD disc media from the drives.

• Remove all PC Card/CardBus adapters from the PCMCIA slots and place them in their protective covers.

• Make sure the main battery is fully seated, or possibly eject the battery for shipping if you suspect the handling will be rough. Your laptop could be seriously damaged if the battery isn't seated properly and the laptop (or bag containing your laptop) receives a sharp blow, forcing the battery to be rammed into the laptop.

• Make sure the system is fully powered off (or optionally in hibernate mode) and not in a suspend or standby mode.

• If the power switch is accessible with the lid closed, make sure the switch is locked or covered so that the system cannot be accidentally powered on while being transported.

• Make sure all access doors and covers are in position and closed.

• Use a carrying case that provides adequate shock protection (cushioning).

If your travel involves flying, you should be aware that FAA regulations now call for more rigorous screening of electronic devices, including laptop computers. The inspections normally require that you remove the system from its travel case and place the unprotected system on the conveyor belt that takes it through the X-ray machine. Make sure you don't put the system upside-down on the conveyor, because that can put pressure on the LCD, potentially causing damage.

In some cases you may be required to power-on the system after the trip through the X-ray machine in order to demonstrate computer functionality. In that situation, be sure you remember to power the system back off (or optionally place it in hibernate mode) before returning it to its travel case. Note that X-rays do not harm either the computer or removable storage media. See "Airport X-Ray Machines and Metal Detectors" in Chapter 10, "Removable Storage," for more information.

If you ever need to ship the system out via the mail or through a package carrier such as UPS or FedEx, it is extremely important that you properly pack the system to prevent damage. In general, it is hard to find a better shipping box and packing material than what the system was originally packed in when new. For that reason, I highly recommend you retain the original box and packing materials after purchasing a system. This will prove to be extremely useful in any case where you need to ship the system to a remote destination.

Following these guidelines for transporting or shipping the system will help to ensure the machine arrives in working order at the destination.

Active Preventive Maintenance Procedures

How often you should perform active preventive maintenance procedures depends on the environment in which you operate your system as well as the quality of the system's components. If your system is in a dirty environment, such as a machine shop floor or a gas station service area, you might need to clean your system every three months or less. For normal office environments, cleaning a system every few months to a year is usually fine. If you frequently use your system outdoors, it may require more frequent cleanings, depending on the amount of dirt and dust in the environment.

Other preventive maintenance procedures include making periodic backups of your data and critical areas, such as boot sectors, file allocation tables (FATs), and directory structures on the disk. Also, you should defragment your hard disks at least once a month to maintain disk efficiency and speed, as well as to increase your ability to recover data should there be a more serious problem. See the section on "Defragmenting Files" later in this chapter.

The following is a sample weekly disk-maintenance checklist:

• Back up any data or important files.

• Delete all temporary files, such as the following:

• *.tmp—Files with a .tmp extension

• ~.*—Files beginning with a tilde (~)

• *.chk—Files with a .chk extension

• Web browser history and temporary Internet files

• Empty the Recycle Bin.

• Check for and install antivirus software updates. If you have a broadband Internet connection, you might prefer to configure your antivirus software program to check automatically for updates daily.

• Finally, run a disk-defragmenting program.

The following are some monthly maintenance procedures you should perform:

• Create an operating system startup disk.

• Check for and install any BIOS updates.

• Check for and install any updated drivers for the video, sound, modem, and other devices.

• Check for and install any operating system updates.

• Clean the system, including the LCD screen, keyboard, and especially the cooling vents.

• Check that the cooling fans are operating properly. Most laptops have only a single fan, but some have more than one.

Many people use a laptop as an accessory to a desktop system. In that case, you may have files that you work with while traveling that need to be synchronized with files on your desktop or on a server. You can use the Windows Briefcase or Synchronization Manager utility to accomplish this. Normally you want to synchronize files every time you disconnect and reconnect to your desktop system or network.

System Backups

One of the most important preventive maintenance procedures is the performance of regular system backups. A sad reality in the computer-repair-and-servicing world is that hardware can always be repaired or replaced, but data cannot. Many hard disk troubleshooting and service procedures, for example, require that you repartition or reformat the disk, which overwrites all existing data.

The hard disk drive capacity in a typical laptop system has grown far beyond the point at which floppy disks are a viable backup solution. Backup solutions that employ floppy disk drives are insufficient and too costly due to the amount of media required. Table 3.2 shows the number of units of different types of media required to back up the 80GB drive in my current laptop system.

Table 3.2 Amounts and Costs of Different Media Required to Back Up a Full 80GB Drive

Assuming the drive is full, it would take 54,883 1.44MB floppy disks, for example, to back up the 80GB hard disk in my current laptop system! That would cost more than $8,232 worth of floppy disks, not to mention the time involved. My laptop includes a CD-RW drive, as do many of the systems today, but as you can see, even using CD-R would be miserable, requiring 109 discs to back up the entire drive. DVD+-R, on the other hand, would only require 18 discs, which still wouldn't be much fun but is much more doable in a pinch. Tape really shines here, because only two DAT DDS-4 tapes are required to back up the entire drive, meaning I would only have to switch tapes once during the backup. Although the media cost is a little higher with the tape as compared to CD/DVD, the time-savings are enormous. Imagine trying to back up a full 300GB drive in a desktop system, which would require 64 DVD+-R discs, but only eight DAT DDS-4 tapes.

Of course, these examples are extreme—most people don't have a full 80GB worth of data to back up. Also, if you organize your system properly, keeping data files separated from program files, you can get away with backing up only the data, and not the programs. This works because in most cases, if there is a drive failure, you will have to reinstall your operating system and all your applications from their original discs. Once the OS and applications are installed, you would restore the data files from your backups.

The best form of backup has traditionally been magnetic tape. The two main standards are Travan and DAT (digital audio tape). Travan drives are generally slower and hold less than the newest DAT drives, but both are available in relatively competitive versions. The latest Travan tape drives store 20GB/40GB (raw/compressed) on a single tape, whereas fifth-generation DAT DDS drives store 36GB/72GB per tape. These tapes typically cost $15 or less. If you use larger drives, new versions of DAT and other technologies can be used to back up your drive.

Another alternative for backup is to use a second, external hard drive of equal (or larger) capacity and simply copy from one drive to the other. With the low cost of drives these days, and the ease of connecting an external drive via USB or IEEE-1394 (FireWire/i.LINK), this turns out to be a fast, efficient, and reasonably economical method. However, if a disaster occurs, such as theft or fire, you could still lose everything. Also, with only one backup, if your backup goes bad when you depend on it, you'll be without any other alternatives.

You can perform hard disk–based backups for more than one system with an external hard drive. External hard disks are available in capacities up to 300GB or more, and if the destination drive is as large or larger than the source, the entire backup can be done in a single operation. Some external hard drive models (such as those from Maxtor) even offer one-button automated backups. Although the upfront cost of an external hard drive can be fairly significant (around $400 for a 250GB model, $200 for a 120GB model, or under $150 for an 80GB model), there is no additional media cost until you want to move some data to permanent tape, CD, or DVD storage.

Cleaning a System

One of the most important operations in a good preventive maintenance program is regular and thorough cleaning of the system inside and out. Unlike desktop systems, laptop systems don't have air flowing through all their parts, so they are more immune to dust internally and normally don't have to be disassembled for cleaning. Laptops do, however, usually have fans that draw air through cooling ducts with heatsinks mounted inside them. Dust buildup in these cooling passages can be a problem because the dust acts as a thermal insulator, which prevents proper cooling. Excessive heat shortens the life of components and adds to the thermal stresses caused by greater temperature changes between the system's full power and sleep/power-off states. Additionally, the dust can contain conductive elements that can cause partial short circuits in a system. Other elements in dust and dirt can accelerate corrosion of electrical contacts, resulting in improper connections. Regularly blowing out any dust and debris from the cooling passages (through the vents) will benefit that system in the long run.

Note that because laptop systems are much more difficult to disassemble, I normally don't recommend opening up or disassembling them just for cleaning. Of course, if you have the system open for some other reason, you should definitely take advantage of the opportunity and clean the interior components thoroughly. For most general preventive maintenance, cleaning the system externally or through any openings is sufficient. This means using either compressed air or a vacuum cleaner to clean dirt out of the keyboard, cooling vents, drive openings, data ports, or any other openings in the system.

Cleaning Tools

Properly cleaning the system requires certain supplies and tools. Here are some items used for cleaning:

• LCD/keyboard/case cleaning solution

• Canned air

• Contact cleaner/enhancer

• A small brush

• Lint-free foam cleaning swabs

• Antistatic wrist-grounding strap

• Computer vacuum cleaner

These simple cleaning tools and chemical solutions enable you to perform most common preventive maintenance tasks.

Chemicals

Chemicals can be used to help clean, troubleshoot, and even repair a system. You can use several types of cleaning solutions with computers and electronic assemblies. Most fall into the following categories:

• Standard cleaning solutions

• Contact cleaner/lubricants

• Dusters

Standard Cleaners

For the most basic function—cleaning exterior LCD screens, keyboards, and cases—a variety of chemicals are available. I normally recommend one of the following:

• 50-50 mixture of isopropyl alcohol and water

• Non-ammoniated glass cleaner

• Pure water (hot water works best)

Other solutions such as antistatic LCD cleaning cloths and Kimwipes are also acceptable alternatives.

The solutions should generally be in liquid form, not a spray. Sprays can be wasteful, and you should never spray the solution directly on the system anyway. Instead, lightly moisten a soft lint-free cloth, which is then used to wipe down the parts to be cleaned.

Contact Cleaner/Lubricants

These chemicals are similar to the standard cleaners but are more pure and include a lubricating component. Although their cleaning applications are more limited when dealing with a laptop system, these chemicals do come in handy for cleaning connectors and internal or external cables. The lubricant eases the force required when plugging and unplugging cables and connectors, reducing strain on the devices. The lubricant coating also acts as a conductive protectant that insulates the contacts from corrosion. These chemicals can greatly prolong the life of a system by preventing intermittent contacts in the future.

A unique type of contact cleaner/enhancer and lubricant called Stabilant 22 is available. This chemical, which you apply to electrical contacts, enhances the connection and lubricates the contact point; it is much more effective than conventional contact cleaners or lubricants. Stabilant 22 is a liquid-polymer semiconductor; it behaves like liquid metal and conducts electricity in the presence of an electric current. The substance also fills the air gaps between the mating surfaces of two items that are in contact, making the surface area of the contact larger and also keeping out oxygen and other contaminants that can corrode the contact point.

This chemical is available in several forms. Stabilant 22 is the concentrated version, whereas Stabilant 22a is a version diluted with isopropyl alcohol in a 4:1 ratio. An even more diluted 8:1-ratio version is sold in many high-end stereo and audio shops under the name Tweek. Just 15ml of Stabilant 22a sells for about $40; a liter of the concentrate costs about $4,000!

As you can see, pure Stabilant 22 is fairly expensive, but only a little is required in any common application, and nothing else has been found to be quite as effective in preserving electrical contacts. NASA even uses this chemical on spacecraft electronics. An application of Stabilant can provide protection for up to 16 years, according to its manufacturer, D.W. Electrochemicals. In addition to enhancing the contact and preventing corrosion, an application of Stabilant lubricates the contact, making insertion and removal of the connector easier. See http://www.stabilant.com or check the Vendor List on this book's CD for more information.

Compressed-Air Dusters

Compressed air (actually a gas such as carbon dioxide) is often used as an aid in system cleaning. You use the compressed-air can as a blower to remove dust and debris from a system or component. Originally, these dusters used CFCs (chlorofluorocarbons) such as Freon, whereas modern dusters use either HFCs (hydrofluorocarbons such as difluoroethane) or carbon dioxide, neither of which is known to damage the ozone layer. Be careful when you use these devices, because some of them can generate a static charge when the compressed gas leaves the nozzle of the can. Be sure you are using the type approved for cleaning or dusting off computer equipment, and consider wearing a static grounding strap as a precaution. The type of compressed-air cans used for cleaning camera equipment sometimes differs from the type used for cleaning static-sensitive computer components.

When using these compressed-air products, be sure you hold the can upright so that only gas is ejected from the nozzle. If you tip the can, the raw propellant will come out as a cold liquid, which not only is wasteful but can damage or discolor plastics. You should use compressed gas only on equipment that is powered off, to minimize any chance of damage through short circuits.

What I recommend with laptops is to turn them sideways or upside down (with the power off) and use the compressed air to blast any junk out of the keyboard as well as any openings on the front, sides, or rear, especially any cooling vents. If you have the system open for any reason, you should take advantage of the opportunity to use the compressed air to blow any dust or dirt out of the interior as well.

Vacuum Cleaners

Some people prefer to use a vacuum cleaner instead of canned gas dusters for cleaning a system. Canned air is usually better for cleaning in small areas as is usually the situation with a portable system. A vacuum cleaner is more useful when you are cleaning a larger desktop system loaded with dust and dirt. You can use the vacuum cleaner to suck out the dust and debris instead of simply blowing it around on the other components, which sometimes happens with canned air. Still, vacuum cleaners are especially useful for sucking dirt out of keyboards, whether on a laptop or desktop system. I also recommend vacuuming the cooling vents on laptops, which is an easy way to remove dust without having to open the unit.

For onsite servicing (when you are going to the location of the equipment instead of the equipment coming to you), canned air is easier to carry in a toolkit than a small vacuum cleaner. Tiny vacuum cleaners also are available for system cleaning. These small units are easy to carry and can serve as an alternative to compressed-air cans. Some special vacuum cleaners are specifically designed for use on and around electronic components; they are designed to minimize electrostatic discharge (ESD) while in use. If you are using a regular vacuum cleaner and not one specifically designed with ESD protection, you should take precautions, such as wearing a grounding wrist strap. Also, if the cleaner has a metal nozzle, be careful not to touch it to the circuit boards or components you are cleaning.

Brushes and Swabs

You can use a small makeup brush, photographic brush, or paintbrush to carefully loosen the accumulated dirt and dust inside a laptop PC before spraying it with canned air or using the vacuum cleaner. Be careful about generating static electricity, however. In most cases, you should not use a brush directly on any circuit boards, but only on the case interior and other parts, such as fan blades, air vents, and keyboards. Wear a grounded wrist strap if you are brushing on or near any circuit boards, and brush slowly and lightly to prevent static discharges from occurring.

Use cleaning swabs to wipe off electrical contacts and connectors, disk drive heads, and other sensitive areas. The swabs should be made of foam or synthetic chamois material that does not leave lint or dust residue. Unfortunately, proper foam or chamois cleaning swabs are more expensive than typical cotton swabs. Do not use cotton swabs because they leave cotton fibers on everything they touch. Cotton fibers are conductive in some situations and can remain on drive heads, which can scratch the disks. Foam or chamois swabs can be purchased at most electronics supply stores.

Some companies sell premoistened contact cleaning pads soaked in a proper contact cleaner and lubricant. These pads are safe to wipe on conductors and contacts with no likelihood of ESD damage or abrasion of the gold plating.

Lightweight Lubricants

You can use a lightweight lubricant such as WD-40 or silicone to lubricate the door mechanisms on disk drives and any other part of the system that might require clean, lightweight lubrication. Other items you can lubricate are the access doors for ports and PC Card/CardBus sockets, to provide smoother operation.

Using WD-40 or silicone instead of conventional oils is important because silicone does not gum up and collect dust and other debris. Always use the lubricant sparingly. Do not spray it anywhere near the equipment because it tends to migrate and will end up where it doesn't belong (such as on drive heads). Instead, apply a small amount to a toothpick or foam swab and dab the silicone lubricant on the components where needed.

Obtaining Tools and Accessories

You can obtain most of the cleaning chemicals and tools discussed in this chapter from an electronics supply house, or even your local Radio Shack. A company called Chemtronics specializes in chemicals for the computer and electronics industry. These and other companies that supply tools, chemicals, and other computer- and electronic-cleaning supplies are listed in the Vendor List on the CD. With all these items on hand, you should be equipped for most preventive maintenance operations.

Cleaning Procedures

Before cleaning your system, I recommend a partial disassembly. By partial I mean taking out any items that can be easily removed without using tools. This would normally include the battery, any drives in removable bays, and any PC Cards. This may also include the hard drive in some systems as well. Finally, open the access doors on the sides, back, or base of the system as well. Because of the difficulty of opening the case on most laptops, I do not recommend a complete disassembly just for the purpose of cleaning.

Once any easily accessible devices are removed and the access doors opened, use the canned air to blow out any dust from these areas.

Cleaning Connectors and Contacts

Cleaning the connectors and contacts in a system promotes reliable connections between devices. On a laptop system, the main connector you'll want to clean is that of the battery—both the contacts on the battery and the mating contacts in the system. If there is dirt or dust on the memory modules or sockets, you might want to remove the memory modules, clean the contacts, and then reinstall them. Also, if you disassemble the system and disconnect any flex-cables, it is recommended that you clean and treat the flex-cable contacts before reinserting them into their mating connectors.

To do this, first moisten the lint-free cleaning swabs in the cleaning solution. If you are using a spray, hold the swab away from the system and spray a small amount on the foam end until the solution starts to drip. Then, use the swab to wipe the connectors and sockets. You might consider using Stabilant 22a contact enhancer on these terminals to prevent corrosion and ensure a good contact. Try to avoid touching any of the gold or tin contacts with your fingers, which will coat them with oils and debris that can cause problems later. Make sure the contacts are free of all finger oils and residue.

Cleaning the LCD and Case

To clean the exterior of your laptop system use the following procedure:

Lightly moisten a soft lint-free cloth with either a 50-50 mixture of isopropyl alcohol and water, non-ammoniated glass cleaner, or pure water (hot water works best). Never spray liquid cleaner directly on the system, especially the display or keyboard.

Gently wipe the LCD display with the moistened cloth, and then follow with a dry cloth. Be sure the cloth is not wet enough to drip and that the LCD is completely dry when you're finished. Antistatic LCD-cleaning cloths and Kimwipes are also acceptable alternatives.

Cleaning the Keyboard

Keyboards are notorious for picking up dirt and garbage. If you ever look closely inside a used keyboard, you will be amazed at the junk you find in there! To keep the keyboard clean, I recommend periodically blowing out the dirt with a can of compressed air or sucking it out with a vacuum cleaner.

The best way to use the compressed air is to turn the system upside down and shoot the keyboard with a can of compressed air tilted back on an angle. This will blow out the dirt and debris that has accumulated inside the keyboard, allowing it to fall to the ground rather than into your system. If done regularly, this can prevent future problems with sticking keys or dirty keyswitches. If you are using a vacuum cleaner, you can leave the system in a normal orientation because the vacuum will suck the debris up and out without allowing it to fall deeper inside the system.

Once the dust and dirt are blown out of the keyboard, you can then clean any cosmetic dirt or stains from the keycaps. The best way to accomplish this is to wipe the keycaps with a soft cloth moistened in cleaning solution and then follow with a dry cloth.

If a particular key is stuck or making intermittent contact, you'll want to soak or spray the faulty keyswitch with contact cleaner. This cannot be done with the keyboard mounted in the system because some of the cleaner may drip inside. To prevent that, before attempting to clean the keyswitch, I recommend you remove the keyboard from the system. Consult your owner's manual (or maintenance manual if you have one) for the keyboard-removal procedure. Most laptops have keyboards that can be removed fairly easily. If you don't have a procedure for your system, use the sample procedure listed later in this chapter.

After the keyboard is removed, you can remove the keycap from the problem keyswitch and spray the cleaner into the switch. I usually do this over a sink so that the excess liquid doesn't drip onto the floor. Then replace the keycap, reinstall the keyboard, and test it to see whether the key works properly. If it doesn't, you may need to replace the keyboard with a new one. Normally you cannot replace individual keyswitches. After that, periodic vacuuming or blowing out the keyboard with compressed air will go a long way toward preventing more serious problems with sticking keys and keyswitches.

Cleaning the TrackPoint or Touchpad

The TrackPoint or touchpad pointing devices used in laptops normally require very little or no maintenance. These devices are totally sealed and relatively immune to dirt or dust. Merely blow off the area around the TrackPoint with compressed air, or wipe down the surface of the touchpad with a mild cleaning solution to remove oils and other deposits that have accumulated from handling them. If you have a TrackPoint and the cap is excessively stained or greasy, you can remove it and soak it in some cleaning solution. If the stain won't come out and/or the cap is excessively worn, it would be a good idea to simply replace the cap with a new one. Replacement TrackPoint caps are available in three different designs from a number of sources including Compu-Lock at http://www.compu-lock.com. Toshiba Accupoint caps can be obtained from any Toshiba Authorized Service Provider (ASP). To find the closest ASP, check with Toshiba at http://pcsupport.toshiba.com. Dell track stick caps can be ordered from Dell directly via its Customer Service department.

Hard Disk Maintenance

Certain preventive maintenance procedures protect your data and ensure that your hard disk works efficiently. Some of these procedures actually minimize wear and tear on your drive, which prolongs its life. Additionally, a higher level of data protection can be implemented by performing some simple commands periodically. These commands provide methods for backing up (and possibly later restoring) critical areas of the hard disk that, if damaged, would disable access to all your files.

Defragmenting Files

Over time, as you delete and save files to your hard disk, the files become fragmented. This means they are split into many noncontiguous areas on the disk. One of the best ways to protect both your hard disk and the data on it is to periodically defragment the files on the disk. This serves two purposes: One is that by ensuring that all the files are stored in contiguous sectors on the disk, head movement and drive "wear and tear" are minimized. This has the added benefit of improving the speed at which the drive retrieves files by reducing the head thrashing that occurs every time it accesses a fragmented file.

The second major benefit, and in my estimation the more important of the two, is that in the case of a disaster in which the file system is severely damaged, the data on the drive can usually be recovered much more easily if the files are contiguous. On the other hand, if the files are split up in many pieces across the drive, figuring out which pieces belong to which files is virtually impossible. For the purposes of data integrity and protection, I recommend defragmenting your hard disk drives on a monthly basis.

The three main functions in most defragmentation programs are as follows:

• File defragmentation

• File packing (free space consolidation)

• File sorting

Defragmentation is the basic function, but most other programs also add file packing. Packing the files is optional on some programs because it usually takes additional time to perform. This function packs the files at the beginning of the disk so that all free space is consolidated at the end of the disk. This feature minimizes future file fragmentation by eliminating any empty holes on the disk. Because all free space is consolidated into one large area, any new files written to the disk are capable of being written in a contiguous manner with no fragmentation.

The last function, file sorting (sometimes called disk optimizing), is not usually necessary and is performed as an option by many defragmenting programs. This function adds a tremendous amount of time to the operation and has little or no effect on the speed at which information is accessed later. It can be somewhat beneficial for disaster-recovery purposes because you will have an idea of which files came before or after other files if a disaster occurs. Not all defragmenting programs offer file sorting, and the extra time it takes is probably not worth any benefits you will receive. Other programs can sort the order in which files are listed in directories, which is a quick-and-easy operation compared to sorting the file listing (directory entries) on the disk.

Windows 9x/Me/2000/XP includes a disk-defragmentation program with the operating system that you can use on any file system the OS supports. For older operating systems such as DOS, Windows 3.x, and some versions of NT, you must purchase a third-party defragmentation program.

The disk-defragmentation programs included with Windows are extremely slow and don't offer many options or features, so it is a good idea to purchase something better. Norton Utilities includes a disk defragmenter, as do many other utility packages. An excellent defrag program that works on all operating systems is VOPT by Golden Bow (http://www.vopt.com). It is one of the fastest and most efficient defragmenting programs on the market, and it is very inexpensive. See the Vendor List on the CD for more information on these companies and their programs.

Virus Checking

Viruses are a danger to any system, and making scans with an antivirus utility a regular part of your preventive maintenance program is a good idea. Many aftermarket utility packages are available that scan for and remove viruses. No matter which of these programs you use, you should perform a scan for virus programs periodically, especially before making hard-disk backups. This helps ensure that you catch any potential virus problem before it spreads and becomes a major catastrophe. In addition, selecting an antivirus product from a vendor that provides regular updates to the program's virus signatures is important. The signatures determine which viruses the software can detect and cure, and because new viruses are constantly being introduced, these updates are essential.