I refurbish and repair quite a few laptops. One of the less interesting but important parts of that work is checking every key on the keyboard.
A keyboard can appear perfectly fine until you discover that one letter, function key or modifier does not work. If you do not test every key deliberately, it is surprisingly easy to miss.
There are plenty of keyboard-testing websites, but they assume the laptop already has a working operating system, browser and network connection. There are also bootable hardware-testing tools, but many are much larger than they need to be or include dozens of features that are irrelevant when all I want to test is the keyboard and mouse.
I wanted something I could put on a USB drive, boot on practically any PC and use immediately.
So I built KbdCheck.
A deliberately small tool
KbdCheck is a minimal bootable Linux environment based on Arch Linux.
The entire ISO is around 47 MB. It does not install anything, modify the existing operating system or need an internet connection. It boots directly from a USB drive into the testing interface.
The display shows a complete keyboard. As each key is pressed, the corresponding key is highlighted. This makes it easy to work methodically across the keyboard and spot anything that is missing, stuck or producing the wrong input.
It also includes a simple mouse test, so the buttons, scroll wheel and pointer movement can be checked at the same time.
That is essentially the whole tool. It does one job and boots quickly enough that using it does not become a job in itself.
Why make it bootable?
Running independently of the installed operating system removes quite a few variables.
A laptop may have no operating system installed yet. Windows may be damaged, locked or halfway through its initial setup. A key-mapping problem, accessibility setting or driver issue can also make a software fault look like a hardware fault.
Booting a known environment gives me a consistent test on every machine. If a key fails in KbdCheck, I can be reasonably confident that I am looking at a keyboard problem rather than an operating-system problem.
It is also useful before fitting a replacement keyboard. I can test the new part properly before finishing the repair and handing the laptop back.
Built because I needed it
This was not an attempt to produce another general-purpose diagnostic suite.
I needed a small keyboard-testing tool for my own workshop. I could not find one that worked quite how I wanted, so I wrote it.
It has already justified its existence by finding a faulty U key on a laptop I was refurbishing. The keyboard otherwise appeared to work normally, which is precisely why checking every key matters.
That is the sort of problem small tools are good at solving. They do not need hundreds of features. They just need to remove one repetitive annoyance and produce a clear answer.
Using KbdCheck
Download the ISO and write it to a USB drive using a tool such as Rufus, Balena Etcher or dd.
Boot the computer from the USB drive and the keyboard tester will start automatically. Work through the keys and confirm that each one registers on screen. The mouse test is available from the same interface.
KbdCheck currently requires Secure Boot to be disabled, as the image is not signed for Secure Boot. Nothing is installed on the computer, and the existing disks are not required for the test.
The ISO download is accompanied by a SHA-256 checksum so its integrity can be verified before use.
Free to use
I built KbdCheck for my own workshop, but there was little point keeping the finished tool to myself.
It is free to download and use. If you repair, refurbish or regularly prepare laptops, it may save you a little time as well.
Download KbdCheck from "kbdcheck.com" (https://kbdcheck.com/).
