http://s817.photobucket.com/user/Lit...ibrary/Lamona%
20Extractor%20Fan

Hopefully you can see this.

There should be a shonky hand drawn circuit diagram and three photographs.

From the diagram I can see most of what is going on (I think) but I am
puzzled by the black wires to the indicator light.

I can see that the black wire from the control panel goes to the circuit
board, then links through a couple of resistors and the light (neon I
think) on to the white wire which goes straight back to the -ve terminal
on the choc block wiring centre on the motor housing.

So it seems logical that if buttons 1,2 or 3 are depressed then there is a
common link via the black wire to the fan power light and then back to
mains.

This in turn suggests that the light coming on just indicates that the
switch is functioning, not that any power is reaching the motor.

However I am currently baffled by the other black wire. On the picture of
the back of the circuit board (it is the blob of solder with the diagonal
top like a pointy hat in the top middle/left of the picture) it doesn't
seem to link with any other component.

Assuming that the black wire from the control panel is there to feed the
fan power light, then that just leaves two wires to actually make the fan
run; blue and red.

Is it reasonable to assume that the logic for a 3 speed fan is 1, 2, 1+2?
This at least gives me a basis for testing.

It doesn't seem logical that the black wire carries the "power on"
indicator to the fan power light and also magically always lights the
light. Hang on, what if the black wire is power for speed 1, and the
sequence is 1 (black), 1+2 (say black+red), 1+2+3 (black+red+blue)?

The design may be messing with my head by having the rear terminals
opposite the front switches but not being connected via those switches.

Anyway, some testing to be done slowly and carefully before I can decide
if power is getting through to the motor.

Any advice and views on the general wiring most welcome.

I haven't yet opened up the motor housing itself to confirm that there is
no wiring issue there.

First plan is to test between +ve in (2nd terminal on central block) and
terminals 3, 4, and 5 to see if voltages appear there when expected by
pushing in the switches.

Cheers



Dave R


--
AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 7 Pro x64

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus