Ex ADT dsc premise pro?

Sounds like this is the result of a power cut and also a duff control panel battery,
Replace the battery and set the time/date but in the meantime press the # key to silense the alert.
Ensure there's no mains power to the control panel before you remove the lid.

The keypads should come back up with a new battery,but that's providing it's not a wiring issue.Replacing the battery is always a good cheap starting point.

Be safe.

e manno
July 2013