Cooper Scantronic 9448 alarm?

Have a Cooper Scantronic alarm system . Instruction book say 9448+ but front of small control box by entry is marked 9427 on its front,
Had 3 hour mains power loss last week and system went dead although outside wall box was flashing. I have now fitted a new battery but system is still dead. Control box lights are on but it does not respond to entry code, Switched mains power on and off but nothing happened, Tried putting entry code in to the other control panel in cupboard where battery is located still nothing happens.
Can anyone suggest solution please.