Keyboard Keys Not Working: How to Fix Them

Before you change any setting or pull off a keycap, use the keyboard test at the bottom of this page: press the keys that are giving you trouble and see whether they light up. A key that registers in the browser is physically fine and the cause is software, a layout or the program you were in. A key that stays dark, especially together with its whole row, is hardware.

That check decides which half of this guide you need: the operating system layer first, then the keyboard itself.

Step one: is it the keyboard or the computer?

Scroll down, click on the page and press each failing key a few times. Then compare what you see with this table.

Result in the test	What it tells you	Where to look
Key turns amber then green	The keyboard sends the key. The computer is ignoring it or doing something else with it	Software section below
Key turns green but types the wrong character	Hardware fine; language layout, Num Lock or a remapping tool	Software section, layout and Num Lock
Key never changes colour	No signal reaches the computer	Hardware section, starting with cleaning
Key stays amber after release	The switch is physically stuck, or its release never arrived	Hardware section, cleaning and keycap removal
Key turns red with chatter in the log	The switch bounces and sends a double press	Hardware section, contacts
Whole row or column dark	A matrix line is broken	Hardware section, dead rows
Keys drop out at random on a wireless keyboard	Weak link rather than bad keys	Hardware section, receiver and batteries

If you can, plug the keyboard into a second computer, or a second keyboard into this one, and run the test again. A key that fails on two computers is a hardware fault beyond doubt. A key that fails on one computer with two keyboards is a software fault beyond doubt. On a laptop, any USB keyboard works for this comparison, and the laptop keyboard test has a layout that matches a notebook.

Software and operating system fixes

Work through these in order. Each takes under a minute, and together they cover almost every case where a key tests fine but fails elsewhere.

Windows: Filter Keys and Sticky Keys

Filter Keys tells Windows to ignore short or repeated presses, and it can be switched on by accident by holding the right Shift key for eight seconds. The symptom is keys that only work when pressed slowly and firmly. Open Settings, then Accessibility, then Keyboard, and turn Filter Keys off. Sticky Keys, which is toggled by pressing Shift five times, makes modifiers latch and can make Shift, Ctrl and Alt seem broken. Turn it off on the same screen.

Windows: language layout

If keys type but produce the wrong characters, the layout is wrong: the at sign and the quotation mark swap between US and UK layouts, Y and Z swap on a German layout, and an AZERTY layout moves the whole top row. Look at the language indicator at the right end of the taskbar, and press the Windows key and the space bar to cycle through the installed layouts. Remove layouts you do not use so the shortcut cannot switch to them by accident.

Num Lock and the embedded number pad

On a full-size keyboard, Num Lock off turns the number pad into arrow and navigation keys. On many laptops, Num Lock on turns U, I, O, J, K, L and M into a number pad, so the letters type digits. Press Num Lock, or Fn and Num Lock on a laptop, and try again. The keypad test shows the current Num Lock state and which code each pad key is sending.

Windows: reinstall the keyboard driver

A damaged driver can drop keys or ignore the whole keyboard. Open Device Manager, expand Keyboards, right-click the keyboard and choose Uninstall device, then restart. Windows reinstalls the standard driver on boot. For a gaming keyboard with its own software, also check that no profile has remapped or disabled the key, and that a game mode has not turned off the Windows key.

macOS: Slow Keys, Sticky Keys and input source

macOS has the same accessibility features under System Settings, Accessibility, Keyboard. Slow Keys adds a delay before a press is accepted and makes quick typing drop letters; Sticky Keys latches modifiers. Turn both off. If characters are wrong, check the input source in the menu bar and under Keyboard, Input Sources. The Mac keyboard test explains which Mac keys never reach a browser and how to check them another way.

One program only

If a key works everywhere except one application, the application has bound it. Browsers take F5, F11 and F12, and games bind almost everything. Look in that program's keyboard settings and reset them to default before touching the hardware.

Hardware fixes

Unplug the keyboard, or power the laptop off, before any cleaning that involves liquid or pulling keycaps.

Cleaning a key that does not register

Dust, crumbs and hair collect under keycaps and stop the switch bottoming out. Turn the keyboard upside down and tap it, then blow compressed air into the gaps around the failing key in short bursts. On a mechanical keyboard, pull the keycap with a wire keycap puller and blow directly into the switch. On a membrane or laptop keyboard, work around the edge of the key without lifting it unless you know how its mechanism comes off.

For a sticky key with residue around it, use a cotton swab lightly wet with isopropyl alcohol on the keycap edges and the surrounding plate. Do not pour anything onto the keyboard. Let it dry, then run the test again on that key.

Taking a keycap off

• Mechanical keyboard. Hook a wire puller under two opposite corners and pull straight up. Wide keys like Space and Shift have stabilisers; lift gently and evenly.
• Membrane desktop keyboard. Most caps pull straight up with a plastic puller or a flat tool under one edge. The rubber dome underneath should not be removed.
• Laptop. Scissor-switch caps clip onto a plastic X. Lift from the top edge with a thin plastic tool and let it hinge away from you. If the X comes with it, note how it sat; whether a replacement cap and clip are sold separately depends on the laptop model. Pulling straight up is how the clip breaks.

Contacts, chatter and stuck switches

A mechanical switch that sends two presses for one, which the test flags in red with chatter in the log, has oxidised or worn contacts. Dust it out with air, then try a few drops of electrical contact cleaner into the switch and work the key a hundred times. If that fails on a hot-swap board, replace the switch. On a soldered board, replacing a switch means desoldering, which is a job for someone with the tools.

A membrane key that chatters or stays stuck is usually a worn dome or dirt under it. Cleaning sometimes helps; otherwise a replacement keyboard is the realistic fix.

Cable, port and receiver

A wired keyboard that drops keys or disconnects as you move the cable has a damaged cable or plug. Try a different USB port on the computer itself rather than a hub, and if the cable is detachable, swap it. For a wireless keyboard with a 2.4 GHz receiver, plug the receiver into a port on the front or on a short extension cable away from USB 3 ports and external drives, which produce interference in that band. For Bluetooth, remove the keyboard from the device list and pair it again.

Batteries

A wireless keyboard on low batteries drops presses before it dies completely, and the dropped presses are random rather than tied to one key. Charge or replace the batteries before concluding that a key is faulty.

A whole row or column not working

Keyboards do not wire each key to the controller individually. They use a matrix: a grid of row and column lines, with each key sitting at an intersection. The controller scans the lines and works out which intersection closed. If one row line breaks, every key on it disappears at once, even though every switch is fine. A row or column that goes dark together in the test is that pattern.

On a desktop keyboard the break is usually a cracked trace on the membrane sheet or the circuit board, and on a laptop it is most often the ribbon cable between the keyboard and the motherboard, which can loosen from flex or heat or corrode after a spill. Reseating that cable fixes some laptops. Otherwise the keyboard, or on thin laptops the whole top case, is replaced as a unit. A single dead key is a cleaning job; a dead row is a repair.

Liquid spills

Act immediately. Unplug a desktop keyboard; on a laptop, hold the power button until it is off and disconnect the charger. Turn it upside down on a towel to drain, keep it that way, and leave it for at least 48 hours in a warm, dry room. Do not use a hair dryer or an oven; heat warps the plastic and bakes residue onto the contacts.

Plain water generally leaves a keyboard working once it is dry. Coffee, soft drinks and anything with sugar or milk leave a film that conducts and corrodes, so keys keep failing or start chattering weeks later. A mechanical keyboard can be opened and its board cleaned with isopropyl alcohol and a soft brush; a membrane keyboard rarely survives a sugary spill; a laptop that had liquid reach the motherboard needs professional cleaning before it is powered on again. After drying, run the test and note every key that is still dark, so you can tell a repairer exactly what failed.

Repair, replace or claim the warranty?

Keyboard type	Single dead or chattering key	Dead row or spill damage
Mechanical, hot-swap	Replace the switch yourself	Open and clean the board, or replace the board
Mechanical, soldered	Desolder and replace, or live with it	Usually replace the keyboard
Membrane desktop	Clean; replace the keyboard if that fails	Replace the keyboard
Laptop, keyboard as a separate part	Replace the keycap and clip if sold separately, otherwise the keyboard	Replace the keyboard
Laptop, keyboard built into the top case	Keycap and clip if available	Top-case replacement, get a quote first

Before any of that, check the warranty. A key that fails on its own during the warranty period is normally treated as a defect; spills, drops and wear are normally excluded. Record which keys fail and in what way with the test, note the date, and contact the seller before opening anything, because a visibly opened keyboard or laptop gives them a reason to refuse. Some manufacturers have run extended repair programmes for specific keyboard designs, as Apple did for MacBooks sold from 2015 to 2019, so a search for your model and the word keyboard is worth a minute.

Related tests

The keyboard test on the home page checks every key on a full desktop layout. If keys register but the keyboard feels slow, the keyboard latency test measures reaction time and auto-repeat so you can compare it against another keyboard. If keys drop out only when you press several at once, that is not a fault in the keys but a rollover limit, and the keyboard ghosting test shows which combinations fail.