In order to help you I need some more information, but in the mean time , did you check a fuse panel for blown one?
By dead you mean, nothing, happens if you turn it on, no illumination on display, not a popping sound on speaker's ?
Hi: Again, if you already check the fuse in the back of the radio and it is good, then the power switch is bad.
This is some kind of common failure on radio cars.
I've been repair some many radios because of that, bad news is Audi Radio parts are not easy to get and most cases when you find it are too expensive.
about 2-3 weeks ago i picked up an 03 Jetta glx because i love the 24 val v6 ADF 'with the monsoon system'.. i bought it knowing the radio didn't work. once i found out its a decent clarion with 8 speaker i canceled the din change and tried to find a solution. I just got it & haven't yet bought. the cd rom or book yet but i am going thru the same issue. And every basic was already covered (fuses etc.) i followed tips off U tube and these show no one with a powerless radio. there posting- press the buttons in a sequence but i just have no power or display. did you find out your radio issue? any solution?