Optima G3 Compact won't set- continuous beeping- please help

[DIYNotMe]

Hi
A recent power cut caused the system to default back to factory user code. Took me a while to work this out (constant ringing in my ears while it did) but ever since I re-entered a new user code, the system doesn't ever set properly. Once I exit the house having input the code,the beeping noise continues permanently.
I've only just realized this as I usually wonder off expecting it to arm itself after 30 secs. But yesterday, on returning home, I heard it still beeping before I even opened the front door and triggered the entry beep tone. I've just sat here now testing to see if the system does arm itself after 30 secs but the beeping just continues constantly. The tone omits 3 rapid beeps every second or so.
Can anyone please help me out?

 

[EightyTwo]

My guess is that the whole panel defaulted, not just the code, and needs reprogramming. You could have a problem with Zone 3. You almost certainly have a problem with your backup battery - when was it last replaced? If it's over five years old, hot or it rattles when you shake it, it should be replaced.

 

[DIYNotMe]

Thanks 82,
I also replaced the battery shortly after, as the power cut highlighted that the battery wasn't working. Any further ideas?
Appreciate your help