How can i stop flashing red light?

I moved into a house 4 years ago with an old Accenta alarm keypad on the wall. The keypads power light has never been lit and as the seller didn't leave any instructions we assumed the system had been disconnected. After a fuse blew two days ago, the red light on the box on the outside of the house has been flashing. Could you let me know how to stop it? I can't find a model number on the keypad, but it looks like an old model

Many thanks