JVC MX-KC68 works in standby but clicks off?

Hi, I have recently aquired a JVC MX-KC68 off of my brother in law. The last time he used it was when he wired it up to one of my 500w soundlab speakers using bridged wiring. Im guessing he's blown the amp. Anyway, it sits fine in stand-by but when you switch it on it gets as far as the welcome message and then clicks back off the standby. What is this likely to be and how can I fix it myslef?