at times it freezes for no apparent reason.....I have to turn it off and start it up again. Have you tried doing that?

I'm not kidding.

I've had that.

Turn over your laptop/keyboard over, and you will be amazed at what comes out.

Also, get a can of compressed air at an office supply store. I use these to clean my keyboards from time to time.

Other than a liquid spill or a hard fall, there's usually not much else that can go wrong.

Turn the keyboard over with keys facing down. Give it a vigorous shaking followed by blowing all the dust bunnies from under the various keys. Repeat until no new crud falls out.

A related problem can be caused by one of the cables going to the keyboard assembly not being properly seated. To fix this latter issue requires opening up the laptop and carefully reseat the cables.

Good luck