Siemens Bluephone Payphone CT6D Repair

[DeBeng]

Bit of a newbie to fixing things and I have no idea why my Bluephone isn't working. 
There is power coming into the phone but no power is going to the coin validator or screen.
I've had a look at the board and found a dodgy diode (tested) and two inductors?
The inductor marked L4 seems to have no continuity.
I'm not sure what value the inductors are (if they are inductors) because they seem too big to be the value they say. Either that or I am just wrong at reading the value. The brand of the inductors is siemems.

Pretty new to all this, so i'll be very happy for help!

Thanks, Ben.

[MAS3]

Hi.

Those are inductors indeed.
What's dodgy about the diode ?
Does it short by any chance ?

Didn't you notice the burnt traces surrounding the inductors (certainly L4) and the diode ?
If a trace looks like that and an inductor is gone, you need to go and look for the cause of that.
The inductor seems to have acted as a fuse here.
Inspect those traces too.

[DeBeng]

Yeah I saw the traces and the diode is dodgy because it does not allow any current through either way.

[DeBeng]

just tried powering up the board and one side of the diode ranges from 1.1v - 5v while the other side ranges from -12 to -7 volts. So a replacement diode is definitely needed!