KeyboardTest provides you with a quick and simple way to detect if your keys are working properly and help you measure typing speed. This utility might prove to be of good use if you need to examine a broken keyboard, test your typing skills, and much more.
The application lets you choose from several keyboard profiles. If your keyboard model isn't listed, you can go to the homepage of the developer and check if any of the available models fits your keyboard's description. Unfortunately, my keyboard model was nowhere to be found, on both app's records and homepage. However, I found a model that is a bit similar to my keyboard and I was able to test some of my keys and LEDs. From what I can see, the developer gives you access to old keyboard models.
If you manage to find your keyboard models in the app's list, the app will offer you various way to test your device. The current status of every key you type will be revealed immediately. The color green means your key is fine, while the blue color lets you know the key is broken. Additional info can be found in the built-in help manual.
In my opinion, you should first check if the program has your keyboard model and then decide if it's worth downloading or buying KeyboardTest.