Comms was lost in one way only (917 could transmit but not receive).
What happened to "transmitting blind" procedures? That way they could inform ATC they were continuing to destination. That is, of course, if they had diagnosed the problem as a receiver only one. How many radios does a B773 have? Surely 3 VHF and what about Sat phones, HF etc.
In answer to a previous question: I have rebooted the CB on a non-working VHF radio box and it did function again.