Scantronics 9800 Alarm - External Sounder "Squaks" at night!

[ScaryLegs]

Hi there,
My ageing Scantronics 9800+ alarm system has developed a weird fault. At night the external sounder squaks away to itself sometimes quietly, sometimes loud enough to annoy the neighbours. The control panel shows no faults, and during the day it makes no noise!

Initially I replaced the external sounder battery suspecting that after 20 years it could have failed! But no sucess
Then I removed the external sounder battery, again no sucsess.
I guess by a process of elimination the fault must lie in the main control panel but that it only happens at night is weird.

Has anybody any suggestions.

Cheers

 

[The Pars]

The bell is knackered. Time to replace.

 

[Bigsosij]

I will second replacing the 20 year old bell box

 

[ScaryLegs]

Thanks for the advice.

Yes, that was my next action and one was ordered yesterday. The existing sounder sounds fine on bell the test so I did wonder if the trigger output on the control board was playing up, and if anyone had anything similar occur. I am hoping it is the sounder, other than replacing the main unit battery every 5 years or so the alarm has given me no problems!

Sods law, it made no noise last night!!!!