MacBook Pro Keyboard Problem

[pctechtv]

I have a MacBook Pro that I had a lot of trouble with. I could not get an operating system installed until I cloned the system in an exact same model. When I was trying to set up an OS I could not get the Option key to allow me to choose a boot device. It seemed to just be ignored. Now that a OS (Yosemite) is running, I have other key commands that are also ignored. For instance, every time I press Command + Shift + 3 or 4, I don’t get a screenshot option. It only makes a bump sound. I guess the bump sound means no? When I try other commands that incorporate the Shift, Command, or 3,4 key, they work fine. What is going on here? Is this a known issue? What is the fix for this? Thanks