Some keys don't work
I have a Toshiba Satellite 503d Harman Kardon and it works great, the problem is that some keys don't work. The keys are:
Enter, B, caps lock, A.
A wide range of repair guides and support for the consumer-grade laptop computer line by Toshiba.
Have you done any work on it? If so the ribbon connector may have come a bit loose. Easiest way to check is to take the top plate off above the keyboard, remove the screws that are holding the keyboard down and then removing the keyboard itself. Check the ribbon connector from there and if you need to remove it completely and reconnect the ribbon. I had this happen on a Satellite A100 the process should be identical.