My logic:
if he's tried to jump it (i.e. a known-to-be-good battery on his system), and he still cant hear ANYTHING when he puts the ignition switch to on, I'm led to believe that the swich is deffective. Accessories should come on when it's on acc, then when it's on ON, the fuel pump kicks in, along with stuff like the wipers, etc, and when in start, the starter relay and solenoid start doing their thing.
Sounds like the switch to siragan.