S4 not being read by mac or windows

S4 not being read by mac or windows

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?!?!?!?!?