I have had non-operational IFE three times on CX, twice times while travelling in F from ICN to HKG, and on both flights I was flying on an AA award ticket. I was given $100USD inflight duty free vouchers on both flights, without asking for anything.

The third time was HKG to JFK in J, on a RTW ticket. It was out for the whole plane, and my wife and I were both given $250US vouchers I think (might have been 200).

It won't hurt to ask for something.
I think you'll find CX may well give you something for a 15+