You can only do that by replacing all the keyboard keys, where you need to be well experienced to perform the operation since there is head involved and if not well done you end up frying the chassis. The best option will be to replace with a new keyboard. If this is helpful, do not forget to mark.Tx
Yes, This could be a fault on the Newly installed LCD. Use a totally different new LCD that you know its working and you will be sorted. Continue using the faulty new LCD and you risk damaging the digitiser port on the board.Be careful.
Plug your headphones back in. Play a bit of sound through them (e.g., a song), then stop the sound. Make sure Preferences is quit. Launch Preferences and open the Sound pane. While the Sound pane is open and set to Headphones, pull out the headphone plug from the jack. It will reset itself to "Internal Speakers" and you are good to go... this should work.as it worked for me