Hi all, 

I have an 10 year old Micron Z6020c alarm system and are having trouble changing the backup battery.  Well changing it is easy, disabling the siren after the fact is not.
I thought this would be an easy diy task but it doesn't seem to be, wondering if anyone has any ideas before I reluctantly call an Alarm tech.

So, the AC light was continually flashing, which alerted us that the battery was low.
I purchased a new one, turned off the power to the alarm and swapped it out. As soon as the new battery was connected the siren started. I turned the power back on the entered the disarm code in the keypad.  The internal siren stopped however the outside one kept going. Arming and Disarming didn't do anything. And after a while the internal siren started again.
There doesn't appear to be a tamper switch on the main alarm box and if I put the old battery back it seems to be ok.

The Alarm manual doesn't mention one word about the battery either, let alone how to change it. And google doesn't offer any advise.
Has anyone successfully changed a battery?  I wouldn't have thought that this would required a tech, perhaps it has to be put into a service mode or a reset performed or something like that?

Also have been reading other posts on Micron alarms and it sounds like these aren't known for being too reliable. But this one does the trick for what we need so not wanting to replace it if I can get away with it.

Thanks