I want to reset my alarm - accenta8 MINI?

We had a powercut and lost electricity for 22 hrs. Alarm went of and would not stop for a long time. when the power came back on I noticed the keypad numbers were lit up but nothing else. None of the LED lights are on ( ie the day LED or the POWER LED).
Pressing my code into the key pad does nothing and makes no noise at all.
What do I do. How do I get the alarm system to work again.