Hu 655 just buzzing, with no audio (video included)

[oumdadzn]

I bought this s40 2004 classic, it is equipped with hu-655 radio, but it never worked except once till i turned the car off.

It does emit a high pitch buzzing sound for couple of seconds than silence for 4 secs than repeat again and again.

Here is a video i took of it:

Can anybody point me to the possible problem? Thank youuu