2009 Vauxhall Combo cd 30 radio unit not changing station or playing cd's.

I have removed and re-installed the Radio unit. When I power it up it scrolls through the Wave band and then settles on 1 Station - pressing either of the 6 buttons or any on the face of the Radio will not get it to change station - the only button on the Radio that is working is the On / Off button. It also will not eject or play a CD.
If I remove the Radio - disconnect the connector and Aerial the n re connect and power up - it may settle on the previous Station or find another one and stick there.

Any help / advice greatly appreciated.