Some keyboard keys not working.

Yes it is time to replace the keyboard.

It is made up of two flexible printed circuits separated by a sheet of plastic with holes at the appropriate junctions to allow the printed circuits to contact when a key is pressed.

What most likely has happened is tha one of the traces has deteriorated and left the contacts for those keys open. The silver print is often damaged by mosture and flexing.

Repairing the circuit is seldom successful and the keyboard is a real nightmare to disassemble and reassemble correctly.

Since generic keyboards are quite reasonable now it is hardly worth the effort unless you are just curious about how it's made.

When you buy a replacement I do recommend going to a store like Office Max where they display them and you can try the layout and feel before buying to improve your satisfaction with it.

Gnack

Yes well I removed 18!! screws and still could not get it apart, like trying to get into fort Knox. Suppose if I am throwing it away I may as well force it open if I can be bothered to unscrew it again.

I do have an old keyboard (obviously) which is OK but it's very cheap and the keys a little stiff for my liking, also it's nice to have a backup, as I found, so I will keep it as a back up. I also have a old flexible keyboard but thats gone out of shape. I might go for a wireless but only if the batterys last a real long time.