As I see it. To disable the ACARS, both VHF & Satcom, the aircraft Information System (AIMS) would have to be disabled, 8 circuit breakers on the flight deck, amongst lots of other systems this would take out the FMS so no information to the moving map in the cabin and the flight instrument display system, But the Satcom C/Bs are in the MEC, downstairs, so the satcom would still be logged on to a satellite, (pinging ?), the aircraft could be flown on basic, standby instruments and raw navigation, the ATC transponder c/b's are also on the flight deck so that could also be disabled. That's the how, the why and where I don't know...neither does anyone else apparently??