This particular topic, not specific incident, was beaten to death some months ago on Prune. Would you wouldn't you? I've had it at FL 160 climbing towards the Alps. I'm not paid to second guess the systems. Whip it around, descend to departure airfield and let the engineers decide it was a wiring problem. On an ETOPS sector with 3 hours to diversion; that's for another time to discuss; but it will happen one day.