have just been given an s4, not brand new but i've been assured it is in working order (guy has no reason to lie)

never used a controller before so i'm hoping its just something incredibly stupid that i'm missing.

I've downloaded relevant drivers etc, but when i turn it on all lights initially light up but after that the master LED light just flashes and nothing else.

It cant be found as a device on either brand new imac or toshiba satellite laptop (intel i3 2.1ghz, 4gb ram)

Is there something i may be missing? or does it sound like the controller is just screwed?!?!?!?!?