digital not working on musical fidelity a3

i just recently recieved a musical fidelity a3 and when i got it the digital rca input wasnt working but the optical and analog connections are but i want to use the digital and let anthem processing i took the led of and evrything is still soldered together what would be the next thing to try thanks for all the help
Sorry,I don't have an answer to your question,but I belive you can find help with at