Diegotte :
1shado1, I haven't tried re-seating the keyboard ribbon cable, do you think it could be the problem?
Nah. Just thought I'd post a random solution, LOL.
But seriously, it COULD be the problem, but no guarantee. Certainly worth the 2 minutes time it takes to check.
Have you tried plugging in an external keyboard?
If it ends up being a bad keyboard on your lappy, don't fret. I got a replacement keyboard for my L355 Satellite for less than 20 bucks including shipping on ebay.