This is probably a very silly question but I tried searching but didn't find an answer.

My mouse pad and left and right click is working but the key input isn't working. I can't type basically. I know there is a key with a lock sign on it and I tried pressing fn or ctrl and then the key to see if I locked it but no luck. I've done a cold boot with the pad docked and undocked but nothing. I can't help think that I have just locked it somehow or changed a setting somewhere by accident.

Can anyone help?