My Macbook keys were not working suddenly one day so I showed it to Apple Authorized Center and they told me after 2 weeks that my mac needs a new logic board and they quoted me 7500 HKD to replace it. I ask them to return my computer and I paid 700 for service charge.
Later my friend gave me this no. Macwin Technology which specialize in fixing Apple products and i thought let me give it a try. The technician there told me i just need to replace the keyboard panel and he charged me 1800 HKd and i got my computer fixed in 2 days. I was very happy and I recommend to go there as people over there are very honest and polite.