Keyboards Problems

Keyboard problems

Your keyboard might seem broken. Here’s what to do.

Wet keyboard

If your keyboard got wet (because you spilled water, coffee, soda, or some other drink), turn the computer off immediately (because water can cause a short circuit that can shock & burn the keyboard and computer and you). Unplug the keyboard from the computer.

Turn the keyboard upside-down for a few minutes, in the hope that some of the liquid drips out. Then let the keyboard rest a few hours, until the remaining liquid in it dries.

Try again to use the keyboard. It will probably work fine. If the keyboard doesn’t work yet, do this:

Unplug the keyboard again. Submerge and wash the keyboard in warm water (you can even put the keyboard into a dishwasher!) but use no soap. Dry off the keyboard. Wait a day for the keyboard to dry thoroughly. If still no luck, the keyboard has been permanently damaged, so buy another.

Dead keyboard

If pressing the keyboard’s letters has no effect, either the keyboard is improperly hooked up or the computer is overheating or you’re running a frustrated program (which is ignoring what you type or waiting until a special event happens). For example, the program might be waiting for the printer to print, or the disk drive to manipulate a file, or the CPU to finish a computation, or your finger to hit a special key or give a special command.

Try getting out of any program you’ve been running. Here’s how:

Press the Esc key (which might let you escape from the program) or the F1 key (which might display a helpful message) or ENTER (which might move on to the next screenful of info) or Ctrl with C (which might abort the program) or Ctrl with Break.

If the screen is unchanged and the computer still ignores your typing, reboot the computer; then watch the screen for error messages such as “301” (which means a defective keyboard), “201” (which means defective RAM chips), or “1701” (which means a defective hard drive).

If the keyboard seems to be “defective”, it might just be unplugged from the computer.
Make sure the cable from the keyboard is plugged tightly into the computer. To make sure it’s tight, unplug it and then plug it back in again.

If you stand behind the original IBM PC (instead of a newer computer), you’ll see two sockets that look identical. The left one (which usually has the word “Keyboard” and a “K” next to it) is for the keyboard cable; the other is for a cassette tape recorder (which nobody uses).
Underneath a keyboard built by a clone company, you might see a switch marked “XT - AT” (or simply “X - A”).

Put that switch in the XT (or X) position if your computer is an IBM XT (or an original IBM PC or any computer containing an 8088 CPU). Put the switch in the AT (or A) position if your computer is an IBM AT (or any computer containing a 286, 386, or 486 CPU).

If you don’t see such a switch, make sure your keyboard was designed to work with your computer.
If fiddling with the cable and the XT-AT switch doesn’t solve your problem, reboot the computer and see what happens.

Maybe you’ll get lucky.
Maybe some part of the computer is overheating. Here’s how to find out:
Turn the computer off. Leave it off for at least an hour, so it cools down.

Then turn the computer back on.

Try to get to a C prompt.

After the C prompt, type a letter (such as x) and notice whether the x appears on the screen.
If the x appears, don’t bother pressing the ENTER key afterwards. Instead, walk away from the computer for two hours — leave the computer turned on — then come back two hours later and try typing another letter (such as y).

If the y doesn’t appear, you know that the computer “died” sometime after you typed x but before you typed y. Since during that time the computer was just sitting there doing nothing except being turned on and getting warmer, you know the problem was caused by overheating: some part inside the computer is failing as the internal temperature rises. That part could be a RAM chip, BIOS chip, or otherwise.

Since that part isn’t tolerant enough of heat, it must be replaced: take the computer in for repair.

That kind of test — where you leave the computer on for several hours to see what happens as the computer warms up — is called letting the computer cook.

During the cooking, if smoke comes out of one of the computer’s parts, that part is said to have fried. That same applies to humans: when a programmer’s been working hard on a project for many hours and become too exhausted to think straight, the programmer says, “I’m burnt out. My brain is fried.”

Common solutions are sleep and pizza (“getting some z’s & ’za”).
When computers are manufactured, the last step in the assembly line is to leave the computer turned on a long time, to let the computer cook and make sure it still works when hot. A top-notch manufacturer leaves the computer on for 2 days (48 hours) or even 3 days (72 hours), while continually testing the computer to make sure no parts fail.

That part of the assembly line is called burning in the computer; many top-notch manufacturers do 72-hour burn in.

Sluggish key

After pressing one a keys, if the key doesn’t pop back up fast enough, probably there’s dirt under the key. The “dirt” is probably dust or coagulated drinks (such as Coke or coffee).
If many keys are sluggish, don’t bother trying to fix them all. Just buy a new keyboard (for about $20).

If just one or two keys are sluggish, here’s how to try fixing a sluggish key:

Take a paper clip, partly unravel it so it becomes a hook, then use that hook to pry up the key, until the keycap pops off. Clean the part of the keyboard that was under that keycap: blow away the dust, and wipe away grime (such as coagulated drinks). With the keycap still off, turn on the computer, and try pressing the plunger that was under the keycap.

If the plunger is still sluggish, you haven’t cleaned it enough. (Don’t try too hard: remember that a new keyboard costs just about $20.) When the plunger works fine, turn off the computer, put the keycap back on, and the key should work fine.


Caps

While you’re typing, if each capital letter unexpectedly becomes small, and each small letter becomes capitalized, the SHIFT key or CAPS LOCK key is activated.
The culprit is usually the CAPS LOCK key.

Probably you pressing it accidentally when you meant to press a nearby key instead. The CAPS LOCK key stays activated until you deactivate it by pressing it again.
Cure:
Press the CAPS LOCK key (again), then try typing some more, to see whether the problem has gone away.

If your keyboard is modern, its top right corner has a CAPS LOCK light. That light glows when the CAPS LOCK key is activated; the light stops glowing when the CAPS LOCK key is deactivated.

If pressing the CAPS LOCK key doesn’t solve the problem, try jiggling the left and right SHIFT keys. (Maybe one of those SHIFT keys was accidentally stuck in the down position, because you spilled some soda that got into the keyboard and coagulated and made the SHIFT key too sticky to pop all the way back up.)

If playing with the CAPS LOCK and SHIFT keys doesn’t immediately solve your problem, try typing a comma and notice what happens. If the screen shows the symbol “<” instead of a comma, your SHIFT key is activated. (The CAPS LOCK key has no effect on the comma key, since the CAPS LOCK key affects just letters, not punctuation.)

If pressing the comma key makes the screen show a comma, your SHIFT key is not activated, and any problems you have must therefore be caused by the CAPS LOCK key instead.

Perhaps the CAPS LOCK key is being activated automatically by the program you’re using. (For example, some programs automatically activate the CAPS LOCK key because they want your input to be capitalized.)

To find out, exit from the program, reboot the computer, get to a C prompt (in DOS) or WordPad (in modern Windows), and try again to type. If the typing is displayed fine, the “problem” was probably caused by just the program you were using — perhaps on purpose.

In some old Leading Edge Model D computers, the ROM has a defect that occasionally misinterprets the signals from the CAPS LOCK and SHIFT keys. When that happens, tap those keys until the display returns to normal.