Today I moved the sensor from the back, back to the front, so now I have 4 on the front again. While I was doing this, I plugged each head into the central power unit and each one gave a test signal as I pugged it in. All except one of the heads (not the one I have just moved) To eliminate a faulty port on the power module, I removed each other head plug and tried plugging the faulty one into different ports. NADA. LED stays green and no signal when it plugs in. (slight sound like a swich is heard faintly in the power box) On the other 3 heads as you plug them in the led goes red and speaker beeps, the start up tone.
On the faulty one, nothing.
To eliminate some broken wire or something, I cut all the excess wire off and rejoined the cable minimal excess. Still nothing. While doing the join, I happened to touch the red and blue wires together and in that state, it seemed to work!!!! With the red and blue touching, it gave proper start up signal and then reverted back to green LED and standby, when I plugged it into the power module.
So, it it working with the blue and red touching or not? Surely not right for these wires to be touching? Need to know asap, as dont want fine in the meantime.....