veritas R8?

I had a house power failure and the control box (in roof) made a few strange noises and the strobe outside began to flash every 10 secs or so.
keypad unresponsive.
Entered controlbox when power restored and checked battery-12.36v .(when in alarm condition battery voltage 5.8v)
keypad now responsive but does not recognise my original user code. Engineers code (4321)also not accepted.

Am replacing the battery but i will still have no control over the keypad.

Please Help.