Philips Repairs

Philips\Marantz DCC Recorders 900\DD82

I did have several of these machines from the 90's, all worked fine but produced no audio output. If any one has any ideas\help then I would be grateful. I suspect the d\a or a\d or the digital boards. The two plug-in boards in the middle of the main PCB. A demag cassette has possibly been used and damaged the 'front end' cct.