Laptop keyboard test

When to test the keyboard

Test the keyboard when you look at a used laptop, after a keyboard replacement or a clean-out, and if anything has ever been spilled on it. Press every key in turn, including the ones you rarely use: F1 to F12, the arrows, Fn and the number pad.

Common faults and their causes

• A whole row or block of dead keys: a past spill or a loose keyboard cable. When a whole block fails, the cause is usually the cable or the circuit, not the individual keys.
• Keys that need a hard press or stick: dust or crumbs under the key, or a broken key hinge.
• Characters typing by themselves: a key stuck down, or a short caused by moisture.
• Function keys that do nothing: you may need to hold Fn, or the maker's driver isn't installed. That isn't always a hardware fault.

Some keys, such as the Windows key, Esc or F11, are captured by the browser or the operating system. Use the test's keyboard lock mode to try those too.

What to do if you find a fault

• Blow out the dust and try the failing key a few more times.
• Plug in a USB keyboard: if it works normally, the fault is in the laptop's own keyboard.
• More: how to check a used laptop or a used MacBook.