How can I fix my Blaupunkt cd30?

I have a Blaupunkt cd30 in a vauxhall combo van. A few weeks ago I pulled the unit out to wire some rear speakers in, replaced, but accidently damaged the antenna cable, causing poor reception.
I got round to pulling the unit out again today and repaired the antenna. However, on replacing the unit, I found that none of the buttons operate, including on/off and volume. The unit does come on, does a search, and stays on the first station it finds, so i am left with one radio station at the same volume. I 've tried disconnecting the unit and reconnecting, no change. Also tried pressing and holding AS and ON together, and pressing and holding all buttons separately.
I'm stumped, any help?