Keyboards

Keyboards are useful on servers primarily during software installation and when running diagnostic programs. Virtually all servers include PS/2 keyboard and USB ports, enabling you to use a low-cost PS/2 or USB keyboard for entering commands.

Types of Keyboards

Servers can use any of the numerous models of 104-key Windows keyboards, as well as the older, but still serviceable, 101/102-key PS/2 keyboards. Although keyboards with features such as ergonomic design and specialized keys for Internet access and multimedia can also be used, there is no need to install specialized keyboard drivers. The standard keys are sufficient for server setup, configuration, and management.

A USB keyboard can also be used, particularly if the keyboard will be used with a server that's running Windows 2000 Server or Windows Server 2003. USB keyboards don't work as well as PS/2 keyboards on KVM switches if a non-Windows server operating system such as Linux is in use. If you use a USB keyboard on a server, you need to be sure the USB legacy mode is enabled in the system BIOS so you can perform setup, startup, and command-line tasks with the keyboard.

See "The USB Configuration Submenu," p. 301, for USB Legacy mode configuration.

Keyboard Maintenance

One of the best ways to keep a keyboard in top condition is periodic cleaning. As preventive maintenance, you should vacuum the keyboard weekly, or at least monthly. When vacuuming, you should use a soft brush attachment to dislodge dust and other debris.

Many keyboards have keycaps that can come off easily. If you're not careful when vacuuming, you'll have to dig the keycaps out of the vacuum cleaner. You should use a small, handheld vacuum cleaner made for cleaning computers and sewing machines; these have enough suction to get the job done, with little risk of removing your keycaps.

You can also use canned compressed air to blow the dust and dirt out of your keyboard instead of using a vacuum. Before you dust a keyboard with the compressed air, turn the keyboard upside down so that the particles of dirt and dust collected inside can fall out.

On all keyboards, each keycap is removable, which can be handy if a key sticks or acts erratically. For example, a common problem is a key that does not work every time you press it. This problem usually results from dirt or other items like hair or food collecting under the key. An excellent tool for removing keycaps on almost any keyboard is the U-shaped chip puller included in many computer toolkits. You simply slip the hooked ends of the tool under the keycap, squeeze the ends together to grip the underside of the keycap, and lift. (IBM sells a tool designed specifically for removing keycaps from its keyboards, but the chip puller works even better.) After removing the cap, spray some compressed air into the space under the cap to dislodge the dirt. Then replace the cap and check the action of the key.

On some keyboards, when you remove a keycap, you are actually detaching the entire key from the keyswitch. You need to be careful during the removal or reassembly of your keyboard to avoid breaking switches. The classic IBM/Lexmark-type keyboards (now made by Unicomp) use a removable keycap that leaves the actual key in place, enabling you to clean under the keycap without risking breaking the switches. If your keyboard doesn't have removable keycaps, you should consider using cleaning wands with soft foam tips to clean beneath the keycaps.

Spills can be a problem with keyboards, too. If you spill a soft drink or cup of coffee into a keyboard, you do not necessarily have a disaster. Many keyboards that use membrane switches are spill resistant. However, you should immediately (or as soon as possible) disconnect the keyboard and flush it out with distilled water and allow it to dry completely before attempting to reuse it.

However, you might prefer to replace the keyboard with a new one. Given the low cost of today's keyboards, it is easier and faster to replace a liquid-damaged keyboard than to clean it.

Tip

If you expect spills or excessive dust or dirt because of the environment or conditions in which the PC is used, you can purchase a thin membrane skin that molds over the top of the keyboard, protecting it from liquids, dust, and other contaminants. These skins are generally thin enough so that they don't interfere too much with the typing or action of the keys.

Keyboard Troubleshooting

The first time to check for keyboard problems is at initial server startup. The signal lights on the keyboard should blink just after power-on. If they don't, chances are the keyboard or the keyboard port is not working.

Keyboard errors are usually caused by two simple problems:

• Defective cables

• Stuck keys

(Other, more difficult, intermittent problems can arise, but they are much less common than these two.) Defective cables are easy to spot if the failure is not intermittent. If the keyboard stops working altogether or if every keystroke results in an error or incorrect character, the cable is likely the culprit.

To determine whether the keyboard cable is at fault, swap the original keyboard with a known-working spare (most keyboards today do not have easily-removable cables). If the keyboard uses the PS/2 port, turn off the system before swapping keyboards. If the problem persists, the keyboard port itself is probably at fault. If the keyboard was plugged into the PS/2 port, try plugging a USB keyboard into the server.

Many times you first discover a problem with a keyboard because the system has an error during the power-on self-test (POST). Many systems use error codes in a 3xx numeric format to distinguish the keyboard. If you encounter any such errors during the POST, you should write them down. Some BIOS versions do not use cryptic numeric error codes; they simply state something such as the following:

Keyboard stuck key failure 

This message is usually displayed by a system with a Phoenix BIOS if a key is stuck. Unfortunately, the message does not identify which key it is!

If your system displays a 3xx error preceded by a two-digit hexadecimal number, the number is the scan code of a failing or stuck keyswitch. For example, 1c 301 indicates the Enter key is stuck (1c is the Enter key's scan code; 301 indicates a stuck key).

If you don't want to (or can't) swap the keyboard for a known-working keyboard, you can look up the scan code at the Upgrading and Repairing Servers website at www.upgradingandrepairingpcs.com to determine which key is the culprit. By removing the keycap of the offending key and cleaning the switch, you can often solve the problem.

Make sure that your keyboard is plugged tightly in to the keyboard socket. If a KVM switch is used, make sure the cables between the switch and managed servers and those between the switch and the PC used for management are tightly connected.