Intruder Alarm problem

[Johnjogger]

Hi I have a Menvier Security Alarm system - installed over 10 years ago -
Today my wife set the alarm on leaving the house and reset it on entering as is the usual routine. After about half an hour the alarm sounded and on entering the code, the keypad registered Lt - which according to the manual means Lid tamper - Aux tamper or SAB tamper.There is no visual signs of disturbance to the control box casing.
How do I reset to remove the Lt sign and restore the system to function again.
Please help.

 

[Alarm]

Any works going on?

LT is the box lid (The lid to the main panel,TS700 by any chance?)
Or the tamper return from the external sounder. And if done incorrectly the internal sounder tamper.


Not a lot of help really as you have to prove each item.
Check the panel lid is secure and nothing clicks when pressing it. Then the speaker/sounder in the hallway (I assume).

After that is will be external sounder, have you access, or ladders? If it is the external it will be a corroded switch and the whole thing needs changing.