Yamaha Receiver RX-V596 DD Decoder stopped working

[Raj]

My coax inputs stopped working last week and I've been trying to fix ever since. I have been using both inputs for years with no problems but now the DD light is no longer going on and there is no output. I have reset it through the diagnostic menu but still no luck. I have also tried going optical and it still doesn't work. If any one has any ideas or instructions as how to go through the diagnostics or has the service manual I would really appreciate it.
Thanks