Cannot reset my Securit 700L fitted by C & K Securitech?

I wanted to drill some wholes in the wall under the security box. Therefore I thought I'd have a look in the box and check if any wires went down, that's the kind of careful bloke I am. Then this tamper alarm went off. I run over to the alarm control panel, but I don't know the user code. (That was already a job on my list of todo's). So to stop the alarm I removed the fuse from just above the main box. The external alarm went off for about 5 seconds before wailing and dieing. I replaced the fuse, now I have know mains power to the control panel, all I can do is type in digits and get tones. Have you got any advice before I commence CPR?