Optima XL6 panel buzzing

[Lateagain]

Very new here and no nothing about electrics so hope you can help.

Tonight my alarm panel has started to emit a low buzzing/humming noise ....it's works ok and it's not hot. What should I do next.

 

[sparkymarka]

Has the battery been replaced in the last 5 years ? It could be a buzzing transformer , remove battery and see if buzzing stops

 

[Lateagain]

Strangely enough the battery was replaced a month ago. I've opened it up and can hear slight buzzing but can't say where from. If I take out the fuse and run on back up battery alone ..... no buzzing??

 

[sparkymarka]

Transformer....can buzz as they age or under load

 

[Lateagain]

Thanks. So would you say perfectly normal and I'm ok leaving it be