Really, Christ I've heard it all now,
Who in their right mind rips out a SCANTRONIC ! And fits a Yale.
The 9880's that I've worked with don't crash,it's us engineers that crash and reprog them for obvious reasons,but saying that it's possible for yours to have developed a fault???.
Why not replace with newer model?,
Scantronic is a very reliable panel :)
e manno
March 2013