The mysterious connector

Me: Your alarm line is out, issit?
Guard: Dunno.
Me: Let me check your phone too. Is it working?
Guard: Dunno.

Go inside the office, and talked to the person-in-charge, "Your alarm line is out, issit?"

"Yeah, the (alarm guys) came yesterday during their monthly routine check and told me its out"
"Alarm guys? And in those alarm guys who monitor your alarm 24 hours?"
"Yes"
"And no one knows until they came for a check?"
"Yes"
"Are you sure they're monitoring your alarm 24 hours"
"Yes"
"Wow."

[In this case, if they monitor your alarm 24 hours, any problem, their centre would have called you up after a set period of time if your system does not handshake with their monitoring system. So, in this case, the problem could have been happening since their LAST monthly check.]

And they mystery here is, that the connector blocks
are in a bad shape. This is a sign of water seepage but
the box was sealed shut. What is more worrying is the
plastic parts of the connector are crumbling. See the
green stuff coming out of the wire? It has turned to
copper sulphate, via electrolysis.

And it was so bad that the first four wires were affected
until the metal is gone.

So I had to re-route the cables to other pairs and updated the customer of the situation.

"Your Guard's phone extension is also out, you know."
"Really?"
"Have you tried calling them?"
"No"
"Have they tried calling you and complained?"
"No"
"........"