Fault Finding Open Circuit

[marksandsparks]

I installed a Texecom Veritas R8Plus about 3 years ago and haven't had any major problems. However, about a week ago when part setting at bedtime the control panel was making the noise that indicates an open circuit and so wouldn't set. I reset it and part setted again and this time it did set.

Last night the same problem occurred but this time the open circuit sound wouldn't go off so I left the alarm off last night.

After doing some checks this morning I have just found out that Zone 6 is open permanently so for the time being I've excluded this zone until I sort out the problem.

Zone 6 consists of two surface magnetic contacts attached to the front and back doors which are both still in place.

What would be the logical sequence to locate the fault please?

[camerabloke]

take 1 door contact off and short the wires, if this doesnt clear do the same on the other, then replace as required. if that dont clear , then there is a cable fault or the zone on the panel is faulty