Intermittent sounder issue

[BlueDefender]

I have an ETR-6/10N sounder direct-wired into the network port of a VX2. Always worked great for years. Recently it started acting up and showing a fixed 3.9 ft. Sometimes it come back alive on it's own, sometimes it seems if I reset the sounder via the breaker or turn the VX2 off then on, then the sounder comes back alive. Other-times it doesn't respond to rebooting but then just randomly starts working again.

I checked all of the connections and they seem solid, tried moving the power to a different breaker incase it was a faulty breaker. Looking at the manual there is a green LED status light - guess I should try and see what state that is in when the sounder is in it's "3.9 ft" mode, although it's tricky to access when underway.

Any other ideas for troubleshooting?

 

[Johnny Electron]

Looking at the green status light when it happens is a good idea. If you haven't been under the cover of the unit before the problem developed (like to change the power setting with the jumpers) then I would guess it is a circuit problem. I would star by seeing what that light is doing just in case it is a communication or other error. If it is a circuit issue it might be better to find a used BBFF1 (ETR6/10N) or a newer DFF1 or BBDS1 unit to replace it with.