I have an Optima XM system around 9 years old. The exterior box had 3 red lights in sequence flashing. There is only one on now for some time. I have no knowlege of

systems. Can anyone tell me the likely cause and if it is easy to rectify B)

Micmac

I take it that the external box you mrntion is the external sounder?

If it is then you will have to obtain the make model of this unit. Bcause there is a standard with the security industry the majority of control panels can connect to the majority of external sounders.

As for the flashing LEDs maybe one of my fellow installers may recognise the 3 LEDs.

Originaly (in the old days) people like me fitted a comfort LED to the front of the old H & C types boxes. Manufacturers started to fit them when the made the new slim type boxes. Eventually they got flashing LEDs that when are off indicate a tamper or battery fault. (they useally have 2 LEDs)

Sorry I cannot add to this any further but best thing to do is give a description of the box ie square round triangle ect

Had problems with corrosion in some bell boxes.