I faced keyboard not Working issue on my laptop today and I was able to fix that by following the steps below. I know you don't want to change your keyboard which might cost you, just follow this simple step, it might be a little soft issue, not hardware issue
- Turn off the laptop
- Remove AC power if plugged.
- Press and Hold the Power button for more than 60 seconds.
- Then, Start the Laptop as Usual. Hope this will help you.
Then you don't want to replace your keyboard. As my point of view, this is a common issue and not a hardware fault.