Urgent volume issues on a Fiat Stilo 1.2 16v

[LisaW]

I have just brought a used fiat stillo 52 plate amd I am having issues with the cassette stereo. Basically the max volume is switched to off and I have read the manual and tried to switch it on bur it wont come on. My radio volume is virtually non existant until I reach about 30 mph but even then it is very low. I have tried turning it up using the main volume button but this does nothing. it doea not increase or decrease the volume. Does this mean that my stereo is broken or can someone shed some light on my issue. Thanks