Some further information following looking inside case.
Fan extension wiring material x 2. This can only be these two with 3 connections per small plastic connector.
These have a connector at each end and one in the midle. I assume the middle one plugs into the front panel where shown in the manual. The panel has a 'tongue' so the connector can only be fitted one way. Wiring is 2 black red 2 yellow. Going in one direction there is a female connector like the one on the motherboard into which the fan plugs. I assume this accepts the connector from the fan which currently goes into the mobo. This is wired black red yellow corresponding to the fan to mobo connector. I assume the power supplied to the panel connects to the fan by this connector. Since the fan speed is controlled from the panel this seems logical.
In the other direction (from centre connector) go the extra single black and yellow wires mentioned above. There is no red wire here. Black and yellow are at either end of the connector with nothing between.
LCD display for temperature and RPM speed
2 fan RPM and 2 temperature monitor display
Overheat alarm function
support the M/B detection; external signal wire.
I can see the RPM governed by the black/red/yellow wires from the panel and connecting to the fan.
Is the black//yellow something to do with detection e.g., temperature?
Any comments gratefully received.