The anode of the diode is attached directly to three of the resistors
as shown.
I have tried to re-create the circuit board traces on the other side.
The cathode connects to what N_Cook has described as an inductor.
Take a look at this photo:
http://i240.photobucket.com/albums/f...e123/DIODE.jpg
Thanks to everyone for your help so far.
Any chance of finding a replacement for this diode?