When I switch on my Kenwood Stack system, it is just clicking?

I have a Kenwood Stack System which has been playing fine, however recently when I have turned on the system all I get is a continuous clicking and not able to operate any of the system whether it be to play a cd or cassette or radio. Its just a constant clicking all the time, why is this and what do I need to do to solve this problem?

Kath
May 2009