Keyboards (Fig. 25-1) are the classical input device. By manipulating a matrix of individual electrical switches, commands and instructions can be entered into the computer one character at a time. If you’ve used computers or typewriters to any extent, you already have an excellent grasp of keyboard handling. However, keyboards are not without their share of drawbacks and limitations. While today's keyboard switches are not mechanically complex, there are a number of important moving parts. When you multiply this number of moving parts times the 80 to 100+ keys on a typical keyboard, you are faced with a substantial number of moving parts. A jam or failure in any one of these many mechanical parts results in a keyboard problem. Most keyboard failures are hardly catastrophic, but they can certainly be inconvenient. This chapter gives you the information needed to understand and repair computer keyboards.

To understand a keyboard, you must first understand the kinds of switches that are used. In general, there are two types of switches that you should be concerned with; mechanical switches and membrane switches. Both switches are used extensively through out the computer industry, but any single keyboard will use only one type of switch.

A mechanical key switch is shown in Fig. 25-2. Two tempered bronze contacts are separated by a plastic actuator bar. The bar is pushed up by a spring in the switch base. When the key cap is depressed, the actuator bar slides down. This action compresses the spring and allows the gold-plated contacts to touch. Since gold is a soft metal and an excellent conductor, a good, low-resistance electrical contact is developed. When the key cap is released, the compressed spring expands and drives the plastic actuator bar between the contacts once again. The entire stroke of travel on a mechanical switch is little more than 3.56mm (0.140"), but an electrical contact (a make condition) can be established in as little as 1.78mm (0.070"). Mechanical switches are typically quite rugged - many are rated for 100 million cycles or more.

A diagram of a membrane key switch is illustrated in Fig. 25-3. A plastic actuator rests on top of a soft rubber boot. Inside the rubber boot is coated with a conductive silver-carbon compound. Beneath the rubber boot are two open PC board contacts. When the key cap is depressed, the plastic actuator collapses the rubber boot. Collapse forces the conductive material across both PC board contacts to complete the switch. When the key cap is released, the compressed rubber boot breaks its contact on the PC board returns to its original shape. The full travel stroke of a membrane key switch is about 3.56mm (0.140") - roughly the same as a mechanical switch. An electrical contact is established in about 2.29mm (0.090"). Membrane switches are not quite as durable as mechanical switches. Most switches are rated for 20 million cycles or less.

Mechanical and membrane switches offer a number of unique advantages and disadvantages. Mechanical switches tend to be highly reliable, and provide a good tactile feedback when typing (that "clicking" noise we usually associate with offices). On the other hand, mechanical keyboards are more expensive to manufacture, and can be extremely sensitive to spills and foreign matter. Membrane switches are not quite as reliable, and tend to offer a softer, "mushier" feel when typing (some people prefer this feel). Due to the membrane cover used in the keyboard, membrane switches seem to withstand spills and foreign matter better than mechanical switches.

The next step in understanding a keyboard is to learn about the key matrix. Keys are not interpreted individually - that is, each switch is not wired directly to the motherboard. Instead, keys are arranged in a matrix of rows and columns shown in Fig. 25-4. When a key is pressed, a unique row (top to bottom) and column (left to right) signal is generated to represent the corresponding key. The great advantage of a matrix approach is that a huge array of keys can be identified using only a few row and column signals. Wiring from the keyboard is vastly simplified. An 84 key keyboard can be identified using only 12 column signals and 8 row signals.

When a key is pressed, the row and column signals that are generated are interpreted by a keyboard interface IC (typically located on the keyboard assembly itself). The keyboard interface converts the row and column signals into a single-byte code (called a key code or scan code). Two unique scan codes are produced during a key stroke cycle. When the key is depressed, a make code byte is sent along to the system. When the key is released, a break code byte is generated. Both codes are transmitted to the host computer in a serial fashion. For example, a make code of 1Eh is sent when the "A" key is pressed. A 9Eh code is sent when the "A" key is subsequently released. By using two individual codes, the computer can determine when a key is held down, or when keys are held in combinations. Just about every key on a keyboard is typematic - that is, it will repeat automatically if it is held down for more than 500mS or so. Typematic settings can usually be adjusted in the CMOS advanced settings for your system.

Most computers today are prepared for multinational operation. To accommodate the special characters and punctuation used in various different countries, keyboard controllers (KBCs) can be configured to provide scan codes for different languages. Table 25-1 illustrates the make and break codes for conventional keyboards used in the domestic United States.

Once a key is pressed and the keyboard interface converts the key matrix signals into a suitable scan code, that code must be transmitted to the keyboard controller (KBC) on the host computer motherboard. Once key data reaches the keyboard controller, it is converted to parallel data by the KBC, which in turn generates an interrupt that forces the system to handle the key. The actual transfer of scan codes between the keyboard and PC is accomplished serially using one of the interfaces shown in Figure 25-5.

Note that there are really three important signals in a keyboard interface; the keyboard clock (KBCLOCK), the keyboard data (KBDATA), and the signal ground. Unlike most serial communication which is asynchronous, the transfer of data from keyboard to controller is accomplished synchronously - data bits are returned in sync with the clock signals. As you might expect, the signal ground provides a common reference for the keyboard and system. The keyboard is powered by +5Vdc which is also provided through the keyboard interface. It is also important for you to note that most XT-style systems are designed with a unidirectional data path (from keyboard to system). AT-style keyboard interfaces are bi-directional. This feature allows AT keyboards to be controlled and programmed from the PC.

Most technicians are familiar with QWERTY-style keyboards - this is the standard format for typewriters that was adopted in the late 1800s. A popular alternative to the QWERTY keyboard is the Dvorak keyboard. Mechanically and electronically, the Dvorak keyboard is identical to conventional keyboards. Only the key order is different - all of the vowels are located on the left side of your home row (the middle row of letters) in the pattern; AOEUIDHTNS.

Dvorak keyboards claim several advantages over QWERTY models. Most letters typed (~70%) are on the home row, so finger (and wrist strain) can be reduced. With less reach to deal with, typing can be accomplished faster, and with fewer errors. The vast majority of Dvorak words use both hands for typing, where there are thousands of words that demand one-handed typing for QWERTY keyboards - this spreads out the strain on your hands more evenly.

There are two classical methods of implementing Dvorak keyboards; dedicated keyboards, and keyboard conversions. Dedicated keyboards are just as the name implies - you buy a ready-made Dvorak keyboard and plug it in. Although the keys are located in different places, the key codes are the same, so your PC doesn’t know the difference. As a result, you can interchange QWERTY and Dvorak keyboards at will without any changes to the PC or operating system. You can also convert your existing QWERTY keyboard to Dvorak under Windows 95:

• Open the Control Panel and double-click on the Keyboard icon.
• Select the Language page and double-click on the English (United States) entry (or your own default entry for countries outside of the US).
• Select "United States (Dvorak)" from the list that appears.
• Save your changes - you may need to install a diskette with the proper drivers.
• It may be necessary to reboot the system.

Under DOS, you will need a DOS TSR to handle the conversion. For MS-DOS 5.0 through 6.22, you can find the Dvorak TSR on the MS-DOS Supplemental Disk. You can obtain the driver files from Microsoft’s FTP or web site (www.microsoft.com), or from the Microsoft forum on CompuServe (GO MSDOS). Download the file DOS62S.EXE.

NOTE: If you do download and extract these supplemental DOS files, make VERY sure to extract them to a new or temporary directory. Under no circumstances should you allow DOS files to overwrite files in the DOS directory, or anywhere in your Windows directories.

Once the software conversion is made, you will need to exchange the keys on your QWERTY keyboard. Figure 25-6 illustrates the comparison between a QWERTY key layout and a Dvorak key layout. You can use a key pulling tool to physically exchange the key caps, or use key stickers or overlays from Hooleon Corporation at (602)-634-7515 or Keytime at (206)-522-8973. You can also obtain more detailed information directly from Dvorak International at (802)-287-2434.

Keyboards are perhaps the most abused part of any computer, yet they are often ignored until serious problems develop. With some regular cleaning and maintenance, however, a keyboard can easily last for the lifetime of a computer. This part of the chapter shows you some practical techniques for keyboard service.

Virtually all computer keyboards are open to the air. Over time, everyday dust, pet hair, air vapor, cigar/cigarette smoke, and debris from hands and ordinary use will settle into the keyboard. Eventually, accumulations of this foreign matter will cause keys to stick, or will prevent keys from making proper contact (i.e. a key does not work every time it is pressed). In either case, keyboard problems will develop. Fortunately, correcting a finicky keyboard is a relatively straightforward process. First, start by removing the key caps of the offending keys. Be sure to note where each key is placed before starting your disassembly - especially if the keyboard is a DVORAK-type or unusual ergonomic design. To remove a key cap, bend an ordinary paper clip into the shape of a narrow "U", and bend-in small tabs at the tip of the "U" shape. Slip the small tabs under the key cap and pull up gently. Do not struggle with the key cap. If a cap will not come off, remove one or more adjacent caps. If there is a substantial accumulation of foreign matter in the keyboard, you should consider removing all of the key caps for a thorough cleaning, but this requires more time.

NOTE: Avoid removing the <Space Bar> unless it is absolutely necessary, since the space bar is often much more difficult to replace than ordinary keys.

Flip the keyboard upside down and rap gently on the case. This will loosen and dislodge any larger, heavier foreign matter, and allow it to fall out of the keyboard. A soft-bristled brush will help loosen the debris. Return the keyboard to an upright position. Use a can of compressed air (available from almost any electronics or photography store) to blow out the remainder of foreign matter. Since this tends to blow dust and debris in all directions, you may wish to use the compressed air outside or in an area away from your workbench. A medium or firm-bristled brush will help loosen any stubborn debris.

Now that the keyboard is cleaned out, squirt a small amount of good-quality electronics-grade contact cleaner (also available from almost any electronics store) into each key contact, and work the key to distribute the cleaner evenly. Allow a few minutes for the contact cleaner to dry completely, and test the keyboard again before reinstalling the key caps. If the problems persist, the keyboard may be damaged, or the individual key(s) may simply be worn out beyond recovery. In such an event, replace the keyboard outright.

There is an ongoing debate as to the safety of vacuum cleaners with computer equipment. The problem is static discharge. Many vacuum cleaners - especially small, inexpensive models - use cheap plastic and synthetic fabrics in their construction. When a fast air flow passes over those materials, a static charge is developed (just like combing your hair with a plastic comb). If the charged vacuum touches the keyboard, a static discharge may have enough potential to damage the keyboard controller IC, or even travel back into the motherboard for more serious damage.

If you do choose to use a vacuum for keyboard cleaning, take these two steps to prevent damage. First, make sure that the computer is powered down and disconnect the keyboard from the computer before starting service. If a static discharge does occur, the most that would be damaged is the keyboard itself. Second, use a vacuum cleaner that is made for electronics work and certified as "static-safe". Third, try working on an anti-static mat (such as the mat in Fig. 25-7) which is properly grounded. This will tend to "bleed-off" static charges before they can enter the keyboard or PC.

Of all the keys on the keyboard, replacing the <Space Bar> is probably the most difficult. The <Space Bar> is kept even by a metal wire that is inserted into slots on each leg of the plastic bar key. However, you have to get the wire into the slots without depressing the wire. If you push the wire down, you compress the wire and installation becomes impossible. As a general rule, do not remove the <Space Bar> unless absolutely necessary. If you must remove the <Space Bar>, remove several surrounding key caps also. This will let you get some tools under the <Space Bar> wire later on. Once the <Space Bar> is re-inserted, you can easily replace any of the other key caps.

Keyboard problems do not happen suddenly (unless the keyboard is dropped or physically abused). The accumulation of dust and debris is a slow process that can take months (sometimes years) to produce serious, repetitive keyboard problems. By following a regimen of regular cleaning, you can stop problems before they manifest themselves in your keyboard. In normal office environments, keyboards should be cleaned once every four months. Keyboards in home environments should be cleaned every two months. Keyboards in harsh or industrial environments should be cleaned even more frequently.

Turn your keyboard upside-down and use a soft-bristled brush to clean between the keys. This prevents debris that may already be on the keys from entering the keyboard. Next, run the long, thin nozzle of your compressed air can between the key spaces to blow out any accumulations of dust. Since compressed air will tend to blow dust in all directions, you may consider "blowing down" the keyboard outside, or in an area away from your workbench. Instead of compressed air, you may use a "static-safe" vacuum cleaner to remove dust and debris.

Staples and paper clips pose a clear and present danger to keyboards. Although the odds of a staple or paper clip finding its way into a keyboard are generally slight, foreign objects can jam the key, or short it out. If the keyboard is moved, the object can wind up in the keyboard's circuitry where serious damage can occur. When a foreign object falls into the keyboard, DO NOT MOVE THE KEYBOARD. Power down the PC, then locate the object and find the nearest key. Use a paper clip bent in a "U" shape with the ends of the "U" angled inward to remove the nearest key cap. Use a pair of non-conductive tweezers or needle nose pliers to remove the object. Replace the key cap.

Accidental spills are probably the most serious and dangerous keyboard problem. Coffee, soda, and even tap water is highly conductive (even corrosive). Your keyboard will almost certainly short circuit. Immediately shut down your computer (you may be able to exit your application using a mouse) and disconnect the keyboard. The popular tactic is to simply let the liquid dry. The problem with this tactic is that most liquids contain minerals and materials that are corrosive to metals - your keyboard will never be the same unless the offending liquid is removed before it dries. Also, liquids tend to turn any dust and smoke film into a sticky glue that will just jam the keys when dry (not even considering the sticky sugar in most sodas).

Disassemble the keyboard's main housings and remove the keyboard printed circuit assembly. As quickly as you can after the incident, rinse the assembly thoroughly in clean, room-temperature, de-mineralized water (available from any pharmacy for contact lens maintenance). You can clean the plastic housings separately. DO NOT USE TAP WATER. Let the assembly drip dry in air. DO NOT attempt to accelerate the drying process with a hair dryer or other such heat source. The de-mineralized water should dry clean without mineral deposits or any sticky, conductive residue. Once the assembly is dry, you may wish to squirt a small amount of good-quality, electronics-grade contact cleaner into each key switch to ensure no residue on the contacts. Assuming that the keyboard's circuitry was not damaged by the initial spill, you should be able to reassemble the keyboard and continue using it without problems. If the keyboard behaves erratically (or not at all) replace the keyboard outright.

Keyboards are an essential peripheral for all computers except servers. There are many cases where network administrators would prefer to restrict direct access to the server, and prevent potential tampering. Traditional PCs did not allow you disable the keyboard, but newer systems DO offer a CMOS Setup entry that can enable or disable the keyboard. When the keyboard is disabled through CMOS, the PC will boot without suffering "Keyboard not found" errors. Before starting service on a server, it may be necessary to reattach and re-enable the keyboard.

While their appearance may seem daunting at first glance, keyboard systems are not terribly difficult to troubleshoot. This ease is primarily due to the keyboard's modularity - if all else fails, it's a simple matter to replace a keyboard outright. The keyboard's great weakness, however, is its vulnerability to the elements. Spills, dust, and any other foreign matter that finds its way between the key caps can easily ruin a keyboard. The keyboard's PC board is also a likely candidate to be damaged by impacts or other physical abuse. The following procedures address many of the most troublesome keyboard problems.

Companion CD: You can use the SCODE22.ZIP utility on the Companion CD to examine the scan codes for each key. You can use this utility to determine which keys (if any) are not working.

Symptom 25-1. During initialization, you see an error message indicating that there is no keyboard connected. Check your keyboard cable and see that it is inserted properly and completely into the PC connector. Remember that you will have to reboot your system to clear this error message. Try another compatible keyboard. If a new keyboard assembly works properly, there is probably a wiring fault in the original keyboard. Given the very low price of new keyboards, it is usually most economical to simply replace a defective keyboard. If you’re working on a file or network server, see that the CMOS Setup has enabled the keyboard.

If a known-good keyboard fails to function, try the original keyboard on a known-good PC to verify that the keyboard itself is indeed operational. If so, your trouble now lies in the PC. Check the wiring between the PC keyboard connector and the motherboard. Check the connector pins to make sure that none of them have bent or pushed in (resulting in a bad connection. You might also want to check the soldering connections where the keyboard connector attaches to the motherboard. Repeated removals and insertions of the keyboard may have fatigued the solder joints. Reheat any defective solder joints. If the keyboard connector is intact, it is likely that the keyboard controller IC (KBC) has failed. Try booting the PC with a POST board installed (as discussed in Chapter 19). A KBC failure will usually be indicated by the system stopping on the appropriate POST code. You can attempt to replace the KBC, or replace the motherboard outright. If a POST board indicates a fault other than a KBC (such as the programmable interrupt controller which manages the KBC's interrupt), you can attempt to replace that component, or simply exchange the motherboard anyway.

Symptom 25-2. During initialization, you see an error message indicating that the keyboard lock is on. In many cases, the detection of a locked keyboard will halt system initialization. Make sure that the keyboard lock switch is set completely to the "unlocked" position. If the switch is unlocked, but the system detects it as locked. The switch may be defective. Turn off and unplug the system, then use a multimeter to measure continuity across the lock switch (you may need to disconnect the lock switch cable from the motherboard. In one position, the switch should measure as an open circuit. In the opposing position, the switch should measure as a short circuit. If this is not the case, the lock switch is probably bad and should be replaced. If the switch measures properly, there is probably a logic fault on the motherboard (perhaps the keyboard controller). Your best course is to try another motherboard.

Symptom 25-3. The keyboard is completely dead - no keys appear to function at all. All other computer operations are normal. This symptom assumes that your computer initializes and boots to its DOS prompt or other operating system as expected, but the keyboard does not respond when touched. Keyboard status LEDs may or may not be working properly. Your first step in such a situation is to try a known-good keyboard in the system. Note that you should reboot the system when a keyboard is replaced. If a known-good keyboard works, the fault is probably on the keyboard interface IC. You can attempt to replace this IC if you wish, but it is often most economical to simply replace the keyboard outright.

If another keyboard fails to correct the problem, use a multimeter and check the +5V supply at the keyboard connector (refer to Fig. 25-5). If the +5V signal is missing, the female connector may be broken. Check the connector's soldering junctions on the motherboard. Reheat any connectors that appear fatigued or intermittent. Many motherboards also use a "pico-fuse" to protect the +5V supply feeding the keyboard connector. If your +5V is lost, locate and check the keyboard connector fuse. If problems continue, replace the motherboard.

Symptom 25-4. The keyboard is acting erratically. One or more keys appear to work intermittently, or is inoperative. The computer operates normally and most keys work just fine, but there seems to be one or more keys that do not respond when pressed. Extra force or repeated strikes may be needed to operate the key. This type of problem can usually range from a minor nuisance to a major headache. Chances are that your key contacts are dirty. Sooner or later, dust and debris works into all key switches. Electrical contacts eventually become coated and fail to make contact reliably. This symptom is typical of older keyboards, or keyboards that have been in service for prolonged periods of time. In many cases, you need only vacuum the keyboard and clean the suspect contacts with a good-quality electronic contact cleaner.

Begin by disconnecting the keyboard. Use a static-safe, fine-tipped vacuum to remove any accumulations of dust or debris that may have accumulated on the keyboard PC board. You may wish to vacuum your keyboard regularly as preventive maintenance. Once the keyboard is clean, gently remove the plastic key cap from the offending key(s). The use of a keycap removal tool is highly recommended, but you may also use a modified set of blunt-ended tweezers with their flat ends (just the tips) bent inward. Grasp the key cap and pull up evenly. You can expect the cap to slide off with little resistance. Do not rip the key cap off - you stand a good chance of marring the cap and causing permanent key switch damage.

Use a can of good-quality electronics-grade contact cleaner and spray a little bit of cleaner into the switch assembly. When spraying, attach the long narrow tube to the spray nozzle - this directs cleaner into the switch. Work the switch in and out to distribute the cleaner. Repeat once or twice to clean the switch thoroughly. Allow residual cleaner to dry thoroughly before re-testing the keyboard. NEVER use harsh cleaners or solvents. Industrial-strength chemicals can easily ruin plastic components and housings. Reapply power and retest the system. If the suspect key(s) respond normally again, install the removed key caps and return the system to service. As a preventive measure, you might wish to go through the process of cleaning every key.

Membrane keys must be cleaned somewhat differently from mechanical keys. It is necessary for you to remove the rubber or plastic boot to clean the PC board contacts. Depending on the design of your particular membrane switch, this may not be an easy task. If you are able to see the contact boot, use a pick or tweezers to gently lift the boot. Spray a bit of cleaner under the boot, then work the key to distribute the cleaner. If the boot is confined within the individual key, you may have to remove the suspect key before applying cleaner.

If cleaning does not work, your next step should be to disassemble the keyboard and replace the defective key switch(es). Observe the board closely for cracks or fractures. Many key switch design still utilize through-hole technology, but you should exercise extreme care when desoldering and resoldering. Extra care helps prevent accidental damage to the PC keyboard. You also have the more economical option of replacing the entire keyboard assembly outright.

Symptom 25-5. The keyboard is acting erratically. One or more keys may be stuck or repeating. Suspect a shorted or jammed key. Short circuits can be caused by conductive foreign objects (i.e. staples, paper clips) falling into the keyboard and landing across PC board contacts. Remove all power and disassemble the keyboard housing assembly. Once the keyboard is exposed, shake out the foreign object or remove it with a pair of long needle nose pliers or sharp tweezers.

Accumulations of dirt or debris can work into the key actuator shaft and restrict its movement. Apply good-quality electronics-grade cleaners to the key, and work the key in and out to distribute cleaner evenly. If the key returns to normal, you may re-assemble the computer and return it to service. Keys that remain jammed should be replaced. If you can not clear the jammed key, simply replace the entire keyboard assembly outright. If you elect to replace the keyboard assembly, retain the old assembly for parts - key caps, good switches, and cable assemblies can be scavenged for use in future repairs.

Symptom 25-6. You see "KBC Error" (or similar) displayed during system startup. When your computer initializes (either from a warm or cold start) it executes a comprehensive self-test routine that checks the key ICs in the system (i.e. the CPU, memory, drive controllers, and so on). As part of this power-on self-test (POST) routine, the computer looks for the KBCLK signal, along with a series of test scan codes generated by the KB controller IC - you can see the keyboard LEDs flash as the controller sequences through its codes. If either the keyboard clock or keyboard data signals are missing, the POST knows that either the keyboard is disconnected, or the keyboard controller has failed. If you are using a POST board, it will probably be displaying a code corresponding to a KBC error. Unless you have the tools and inclination to replace a KBC controller IC, your best course is simply to replace the motherboard outright.

Symptom 25-7. You cannot clear macros from a programmable keyboard. In most cases, you need to use the right key combination in order to clear the macros. If the keyboard has a <Remap> key, press that first (a Program light or other LED will start blinking). Press the <Ctrl> key twice to map the key to itself. Press <Alt> twice to map the key to itself. Press the <Suspend Macro> key (the Program light should stop blinking). Press the <Ctrl> and <Alt> keys while pressing <Suspend Macro> - this will clear all of the keyboard’s programming. The key sequence used for your keyboard may be different, so be sure to check the procedure for your own keyboard. If problems persist, replace the keyboard.

Symptom 25-8. The keyboard keys are not functioning as expected. Pressing a key causes unexpected results, or a series of operations that would ordinarily not be attributed to that key. Chances are that the keyboard has been programmed with macros, and you’ll need to clear those macros to restore normal keyboard operation. If the keyboard has a <Remap> key, press that first (a Program light or other LED will start blinking). Press the <Ctrl> key twice to map the key to itself. Press <Alt> twice to map the key to itself. Press the <Suspend Macro> key (the Program light should stop blinking). Press the <Ctrl> and <Alt> keys while pressing <Suspend Macro> - this will clear all of the keyboard’s programming. The key sequence used for your keyboard may be different, so be sure to check the procedure for your own keyboard. If problems persist, replace the keyboard.

Symptom 25-9. Some keys on a programmable keyboard will not remap to their default state. This can happen with some Gateway 2000 (AnyKey) keyboards - as well as other programmable keyboards - and you may have to "force clear" the keyboard at boot time. Power down the system. While holding down the <Suspend Macro> key, turn the system power back on. Continue booting with the <Suspend Macro> key depressed until the Program light (or similar LED) quits flashing. This light will stay lit until you depress and release it.

NOTE: For Gateway 2000 AnyKey keyboards, if there is an "AnykeyXX T" line in the AUTOEXEC.BAT file, this will terminate any programming function of the keyboard. If there is an "AnykeyXX A" line in the AUTOEXEC.BAT file, this will activate the programming function.

Symptom 25-10. A wireless keyboard types random characters. You’ll need to reset both ends of the wireless system. First, take a look at the DIP switch settings controlling the RF channel for the wireless transmitter and receiver (usually under the battery cover at the keyboard). Make sure that the transmitter and receiver are both set for the same channel. Find the "Reset" button on both the transmitter and receiver. Press the RF receiver reset button first, then press the RF transmitter button immediately after (usually within 15 seconds of one another). If the problem persists, reboot the system and try the reset process again.

Symptom 25-11. The wireless keyboard beeps while typing. In virtually all cases, the batteries in the wireless keyboard are running low. Replace the batteries and try the wireless keyboard again - the beeping should stop.

Symptom 25-12. Typed characters do not appear, but the cursor moves. This issue is a result of the color scheme being used. Some of the applications reported as suffering this problem are MSWORKS 4.0, CASHGRAF, MSBOB (address book & letter writer), and MSPUBLISHER. Check the color scheme selected by right clicking on the desktop. Click on Properties and then the Appearance tab. Set the scheme to Windows Standard. Click on OK to return to the desktop. The text should now appear normal. This solution can generally be attempted with any application.

Symptom 25-13. Some function keys and Windows keys may not work some PC configurations. For example, this is a known problem with Toshiba 8500 desktop systems and the Microsoft Natural Keyboard. In virtually all cases (including the Toshiba 8500), the PC keyboard controller BIOS recognizes the keyboard during the Power-On Self Test (POST), but it does not recognize some of the keys - including certain function keys and Windows-specific keys. You’ll need to try a generic keyboard, or upgrade the system’s keyboard controller BIOS.

Symptom 25-14. One or more Windows-specific keys don’t work. This is almost always a limitation of the keyboard controller BIOS. For example, a Jetkey keyboard controller BIOS (v.3.0) will not recognize the right Windows key on a Microsoft Natural Keyboard. You’ll need to try a generic keyboard, or upgrade the system’s keyboard controller BIOS.

Symptom 25-15. Remote control programs don’t work after installing keyboard drivers. Many PC "remote control" programs (i.e. PC Anywhere, ReachOut, and Carbon Copy) use keyboard and mouse drivers that are simply not compatible with the keyboard’s specific drivers. For example, the remote control programs listed above will not work when IntelliType software is installed for the Microsoft Natural Keyboard. You’ll need to disable the remote control software, install patches for the remote control software which WILL properly support the keyboard, or replace the keyboard with a more generic model.

Symptom 25-16. On a PS/2 system, you encounter keyboard errors, even though the keyboard driver loads successfully. Often, you’ll see an error like; "Keyboard error: keyboard not found", and you cannot access the keyboard. This type of problem is known to occur on PS/2 systems when the IBM ROM BIOS patch file (DASDDRVR.SYS) is loaded after the keyboard driver in CONFIG.SYS. Rearrange the CONFIG.SYS file to load the DASDDRVR.SYS file before the keyboard driver. Make sure you are loading the patch driver (DASDDRVR.SYS) that is designed for your specific computer (for example, you cannot use the DASDDRVR.SYS file that ships with an IBM PS/2 Model 80 on a PS/2 Model 70 computer). This device driver can normally be found on the SETUP disk that you received with your IBM PS/2. Otherwise, you can obtain it from IBM (www.ibm.com).

Symptom 25-17. Assigned key sounds do not work. When you assign sounds to keystrokes (under the Options tab in the Keyboard tool in your Control Panel), the sounds may play when you press the assigned keys. This problem is known to occur with some programmable keyboards when HiJaak Pro or HiJaak 95 Graphics Suite installed on your computer. These products may load a device driver named "Runner" that disables programmable keyboard sounds. You may be able to work around the problem by closing the "Runner" task:

• Press <Ctrl>+<Alt>+<Del> to open the Close Program dialog box.
• If "Runner" is listed, click Runner and then click End Task.

Symptom 25-18. You cannot use Windows-specific keys to start task switching software other than TASKSW16.EXE. You can start the desired task switching software using <Ctrl>+<Esc>, or by double-clicking the desktop. Chances are that your Windows-specific key will not start any other task switching utility if TASKSW16.EXE can be found on the path. You’ll need to update the task switching program reference in SYSTEM.INI. Load SYSTEM.INI into any text editor, and modify the line that reads:

TASKMAN=TASKSW16.EXE

to read

TASKMAN=<task manager>

where <task manager> is the name of the executable file you want to start when you press the Windows key. Rename the TASKSW16.EXE file (i.e. TASKSW16.OLD), or move it to a directory that is not in the path. Save and close the SYSTEM.INI file, then restart the computer.

Symptom 25-19. The NumLock feature may not activate when the NumLock key is pressed. This can happen with some programmable keyboards when pen software is installed on the system. You should be able to correct the problem by disabling the pen device:

1. Click Start, select Settings, then click Control Panel.
1. Double-click the System icon and select the Device Manager tab.
1. Double-click the Ports entry to expand it.
1. Double-click the port to which the pen (or touch-screen) device is connected.
1. In the Device Usage area on the General tab, click the "Original Configuration (Current)" check box to clear it (if you’re using OSR2, click the "Disable In This Hardware Profile" check box to select it).
1. Click OK, then restart the system when prompted.

NOTE: To enable your pen device again, repeat the steps above, but re-select (or re-clear) the check box in step 5.

That’s all for Chapter 25. Be sure to review the glossary and chapter questions on the accompanying CD. If you have access to the Internet, take a look at some of the keyboard resources listed below:

NMB Technologies: http://www.nmbtech.com/

Keytronic: http://www.keytronic.com

Mitsumi: http://www.mitsumi.com

Microsoft: http://www.microsoft.com/products/prodref/310_ov.htm (Natural Keyboard)

Chicony: http://www.chicony.com/