Aluminium keyboard

Does anybody know of a way of checking the ally keyboard for the Imac. All of a sudden I have lost the letter 'u' and now the spacebar will not work. I am sure there was a firmware update the other day on the keyboard but only had problems this afternoon. Maybe a warranty problem but thought I would ask first.

Thanks

My mom's iMac's keyboard had the same issue, even after the software update. I got it exchanged under warranty.

Many thanks, sorry for the delay. Now in repair shop. As a matter of interest, the next day I lost even more letters. Just hate this keyboard I am having to use, like going back in time!!