tin2080

Hi my home has been fitted with a scantronic 9651 system, it has p.i.rs in all down stairs rooms. The front and rear doors have surface mounted contacts. When I set the system and leave via my front door the alarm continues to beep and will not arm once I close the door. This has happened before and I was advised to replace the door contact which i did, this solved the problem until now! The same thing has happened again I have checked the contact and everything seems to be OK with no loose wires. The contact is grade 2 with a small circuit board inside, it also has a small spring tamper mechanism. Can anyone help? regards Steve