Accenta G4 PCB replacement

[shakattack]

I am looking to swap out a faulty PCB on an accenta G4 alarm.
When I disconnect mains and remove 12v battery the bell sounds. I assume it's the bell tamper.

How can I disable this / silence bell during the PCB replacement preferably without climbing up to the bell box?
Thank you!

 

[sparkymarka]

Put the 12v supply to the bell on the battery …or be really quick swopping it over ….lol

 

[shakattack]

Put the 12v supply to the bell on the battery …or be really quick swopping it over ….lol

Thanks! Will that work with the other bell connections disconnected? Seems like as soon as I remove the tamper one it starts sounding.

 

[sparkymarka]

Removing the tamper wire at the panel won’t make it ring ….removing either the 12+ or 0v will ….these are the two wire you can put on the battery to stop it from sounding

 

[shakattack]

Removing the tamper wire at the panel won’t make it ring ….removing either the 12+ or 0v will ….these are the two wire you can put on the battery to stop it from sounding

Ive just measured with multimeter and mine behaves a bit different. The T and A wires (in SCB header) are both at 12V and the Bell + and - are both at 0.1V.

Am I missing something?

 

[Bigsosij]

Take the wires from the tamper and 0v terminals and cocnnect to the negative terminal of the battery as they may be mixed up at the bell end. Attach 12v supply to positive battery terminal. Thtis should soslve your issue.

 

[sparkymarka]

Measure across A and BELL+ You should have 13.80v DC

 

[shakattack]

Take the wires from the tamper and 0v terminals and cocnnect to the negative terminal of the battery as they may be mixed up at the bell end. Attach 12v supply to positive battery terminal. Thtis should soslve your issue.

Thanks! Okay yes I've managed to do it and power using a mains 12v adapter

 

[shakattack]

Thanks for all the replies. Managed to replace the lm317 voltage regulator on the PCB and reinstall to get everything working again.

I put the bell + into a 12V supply powered from mains.