Keyboard Not Working? How to Find Out Which Keys Are Broken

A keyboard key that doesn't work usually falls into one of three buckets: it never registers at all, it registers sometimes but not reliably, or it registers the wrong character. Each points to a different cause, and figuring out which one you have is the fastest way to know whether you need a new keyboard or just need to fix a setting.

Step 1: Confirm it's the key, not the app

Before assuming your keyboard is broken, rule out software. Open a plain text field (Notepad, a browser address bar, anything with no keyboard shortcuts bound to it) and press the key there. If it still doesn't type anything, it's not an app-specific shortcut conflict — move on to testing the hardware itself.

Step 2: Test every key at once

The quickest way to map out exactly which keys are affected is to use an online keyboard tester and press every key on your board once. Working keys turn green; anything that doesn't respond stays gray, and you get a complete picture in under a minute instead of guessing key by key.

Try the free keyboard tester →

Step 3: Look at the pattern

A single dead key almost always points to one of these:

• Debris under the keycap — dust, crumbs, or a hair caught under the switch. Removing the keycap and blowing it out with compressed air fixes this more often than people expect.
• A worn-out switch — common on keyboards that are several years old, especially on frequently-used keys like spacebar or the letter keys in your dominant hand's home row.
• Liquid damage — if several adjacent keys stopped working around the same time, a spill is the likely cause, even a small one from weeks ago.

If instead several keys in a specific combination fail only when pressed together — but work fine individually — that's a different problem called keyboard ghosting, not a broken key.

Step 4: Try a different USB port or a different computer

If every key seems unresponsive at once, the fault is more likely the cable, the USB port, or a driver issue than every switch failing simultaneously. Testing on a second computer (or a different port) takes thirty seconds and immediately tells you whether the keyboard itself is the problem.

When it's time to replace the keyboard

Mechanical switches are individually replaceable on many keyboards, and a single dead switch is often a cheap, straightforward repair. On membrane keyboards (most laptops and budget boards), a dead key usually means the membrane layer itself has failed at that point, and replacing the whole keyboard is typically more practical than repairing it.