This article explains how to fix it when a mechanical keyboard key isn't working.
If you're having a problem with unresponsive keyboard keys on your mechanical keyboard, then try each of the following fixes in order. If one of these solutions doesn't apply to your specific keyboard, you can skip it.
Don't attempt repairs on a mechanical keyboard or individual switches unless you've unplugged it or removed the batteries.
Here's how to fix unresponsive keyboard keys:
Unplug the keyboard and plug it back in. Doing this usually doesn't fix when just one key doesn't work, but it's also an easy fix that takes almost no time. If your keys start working after you plug the keyboard in, then you're done.
Try a different cable. If your keyboard is connected via a physical cable, try swapping to a different cable and plugging into a different USB port on your computer. If you're using Bluetooth, try connecting with a cable to see if that fixes the problem. If it does, then you might have a Bluetooth driver problem.
Replace the batteries. If you're using a wireless mechanical keyboard that connects over Bluetooth, the connection may be dropping intermittently due to battery problems. Try inserting a fresh pair of batteries, and see if that helps.
Clean the keyboard. The keycaps of the unresponsive keys may be getting stuck on debris. First, try blowing between the keycaps with canned air. If that doesn't work, remove the keycaps, and blow off the keyboard with canned air.
Blow out the unresponsive switch. Pry the keycap off the unresponsive switch, hold the keyboard upside down, and blow out the switch using canned air. If that works, you may want to clean the keyboard at this time to avoid similar problems with other switches.
Use contact cleaner. Unplug your keyboard, remove the batteries, and take the keyboard to a well-ventilated area. Remove the keycap, and insert the contact cleaner nozzle or straw into the stem of the key switch. Apply one or two squirts of contact cleaner, and then work the switch stem up and down and side to side. Then let the contact cleaner dry thoroughly before replacing the keycap and check if the key functions.
Depending on the contact cleaner you use, it may damage your other keycaps. In that case, you may want to remove all of the keycaps before you attempt this procedure. Only use a contact cleaner designed for this purpose.
Inspect the solder joints. If your keyboard has soldered switches, then the solder joints may be broken on one of the switches. If the solder has popped off the circuit board or the switch contacts look loose, you can fix the problem by repairing the solder joints.
Replace the switch. If nothing else works, replacing the switch will usually solve the problem. You need to desolder and remove soldered switches, and then solder in replacement. You can pop hot-swappable switches out with the proper tool, and then you can insert a replacement with no soldering required.
Replace the keyboard. If replacing the switch doesn't fix the problem, there's a more significant issue with the keyboard itself. Your options at that point are to take it to a professional who may or may not be able to repair it or replace it.
If one key, like your A key, isn't working, then it's probably a bad switch or a stuck keycap. The best way to fix it when one key isn't working is to focus on that key. Pop off the keycap and look for debris. If you see anything, clean it out with canned air. If that doesn't work, you can try cleaning the key with canned air or contact cleaner and replace the switch if nothing else works.
If you have a key on a mechanical keyboard that's dead, you can fix it by replacing the switch. Each one has a mechanical switch under it, and you can replace those switches individually. If you have a hot-swappable keyboard, you can pop the switch out with the appropriate tool and then snap a new one in place.
If the key still doesn't work after replacing a hot-swappable switch, the socket may be bad. It isn't common, but hot-swappable switch sockets can wear out.
You can also fix a dead key on a soldered mechanical keyboard by replacing the key, but it's more complicated than replacing a switch on a hot-swappable keyboard. You need to desolder the solder joints that connect the switch to the keyboard, replace the switch, and solder in the new switch. If you aren't comfortable with soldering, this repair is better left to the professionals.
Mechanical keyboard keys can stop working for many reasons. If the keyboard doesn't work at all, it's likely to be a connection or driver problem; However, if just one key stops working, like if your A key is not working while the rest work fine, it's more likely to be a problem with that particular switch.
Here are some reasons that a mechanical keyboard key will stop working:
To make your mechanical keyboard quieter, place foam or a desk mat underneath it and lubricate the switches. If you have clicky switches, replace them with linear ones.
First, try cleaning the keyboard with alcohol and canned air. If you're still having problems, you might have to replace the key.
Mechanical keyboards are easier to repair and more customizable since it's easy to switch out the keys. Some people find mechanical keyboards more comfortable to use.