Accenta 6 Alarm System Unresponsive Keypad - Please Help!?

Hi

I wonder if anyone could help. We have moved into a house that has an Accenta alarm system installed. There are 2 PIR's also, one in the lounge and one on the landing. We changed the code when we moved in and all was working fine. We decided to decorate the kitchen. On the kitchen wall is an unsightly small 3 inch wide by 5 inch high (approx), silver box. It has an opening at the top of the box and inside is a piece of wood. The front panel of the box has a keyhole and there is a key. By turning the key just moves the box up and down. There is a similar box on the landing as well we've noticed. There are no wires or anything going into these silver boxes and so, having no idea what these silver boxes are, and because they are unsightly, I decided to remove it when we were decorating. However, as I tried to do this it activated the alarm. I entered the code which turned the alarm off, but left the alarm keypad unresponsive. The, Attack, Day and Power lights were illuminated. I opened the alarm central control panel and took a wire off the battery, fiddled with the silver box again to see if I could work out what it does, this time the alarm didnt activate so I went back to the keypad and in addition to the Attack, Day and Power lights, the Tamper light is now on.

I read a solution on this site to a similar problem and so I tried it, but it didn't work unfortunately. Here's what I did. I unclipped a battery lead, turned off the mains power, and this activated the alarm, I keyed in our code which de-activated the alarm, I clipped the battery lead back in, but once again the keypad is unresponsive and now the Day light has gone out but the Attack, Tamper and Power lights are on.

I've looked at the glass fuses and they all seem ok (however not sure what I'm looking at to be honest but the all seem to have a piece of fusewire intact).

Could anyone help advise us what we need to do to rerstore our alarm to a functioning one, we'd be most grateful. Do we need to call an alarm engineer out, if so how expensive will that be? And what are these blasted silver boxes for?

Thank you in advance