I think I know what the beeping is now that you mention it. Because the bulb has failed behind the clock part of the OBC, I had to set the clock by looking closely at the dim characters. I do recall hitting the Memo button (or something) which normally puts the chime icon above the clock (as far as i remember).
I think I better try another OBC in the car (they seem pretty easy to pop out) and give it a try. If its the actual computer that is duff, then I guess I have been given a faulty ultimate driving machine
thanks guys for your reply though. its appreciated