Electronic Alarms and Home Security Devices - Door contact repair / replacement

My front door does not seem to be registering with the system when opening and closing. It is linked in with the garage door in the 1st zone of our DSC 1555 system. I tapped the contacts as mentioned in some of the previous posts, but that did not seem to affect anything. The contacts are a flush mounted magnet in the frame and door. Questions are...

1. Is there anything else I should try before replacing?

and...

2. If / when replacing, am I replacing both the contact in the door and frame, or just the one?

The system is wired (as opposed to wireless) so I assume I will just splice the new contacts in with the old wire that would come through the frame contact? The door contact just pulled right out without any wires....

Thanks!!

The piece in the door is just a magnet, all you normally need to replace is the switch. The simplest test is to get the old contact out of the door frame (don't be surprised if it comes out in pieces) and twist the pair of wires together, if the zone closes, then all you need is a new contact.

Will do that this evening. Although, the zone is currently showing as closed now, it just doesn't register anything if the door opens. Is it possible it's just not recognizing that door at all??

It's pretty common for contacts to fail in the stuck closed position. Same difference, your zone should open when the wire is disconnected. The simple, non destructive test is to take the zone wire off the zone terminal on the motherboard.

Zone programming rarely changes spontaneously, (and then only on older systems that don't have the more stable eeproms used in the last 10-15 years).