For the past couple weeks I’ve been connecting an external keyboard to my Macbook Pro simply because the keys on the keyboard were not working – specifically the top row (E thru P). I finally got some free time and did some digging around, watched YouTube clips, read blogs and found one simple trick. Are you ready? Here it is:
Quick tip: Keyboard on a Macbook Pro is not responding
Click on the OPTION button 5 times.
Can someone… anyone please explain to me the theory behind this trick? It worked like a charm, now to be honest my keyboard still slips up from time to time, but clicking on the OPTION button 5 times once again resets the keyboard and instantly it starts working again.
I am not by-far a professional with the MAC so I am not saying that this is the catch-all trick and call it dumb-luck but it just works for me. If you have issues with your keyboard try this trick and let me know if it works for you. If your a professional and know the meaning behind this trick please share – and if you know more tricks, please share those as well.
Here are the specs of my Macbook Pro just in case it may only be for the same make and model:
MacBook Pro (15-inch, Mid 2010)
Processor: 2.4 GHz Intel Core i5
Memory: 8 GB 1067 MHz DDR3
Update:
Ask and you shall receive. Thanks for the speedy response Nikki!
OS X: Unable to type while Mouse Keys is enabled
If you are unable to type letters, numbers, or symbols, you may have Mouse Keys enabled on a keyboard that has no numeric keypad or Num Lock key. If you log in as a different user (who does not have Mouse Keys enabled), you may be able to type numbers using some keys, but not letters.
Jason Uzarraga 
You just saved my entire day (and possibly more). I can’t thank you enough.