0-12V Adjustable Home Made DC Source not working
With ABOUT 18V on LM317 input:


Short ALL 3 pot connections together.
You should get about 1.2V output.  


If not 1.2V check LM317 input.  


If LM317 input is ~= 18V and all pot pins are shorted and Vout not ~= 1.2V the LM317 is dead. 
If LM317 input is loaded down to &lt;&lt; 18V something is wrong with cct shown.


If LM317 output is ~= 1.2V then 

Turn pot to half position.
Measure resistance between pins AB BC CA
One pin will measure ~= 5k/2 to other two.
Two pins will measure 5k between them (if 5k pot) 
~= half R pin is wiper.

Connect one end pin to known cct ground.
Connect wiper pin with pot set to half setting to each of 3 pot pins on PCB in turn.

When wiper is on correct pin Vout will be ABOUT (2500 + 220)/ 220 * 1.2 = ABOUT 15V.
As pot may ne lin or log or ??? mid point may not be half Resistance position so Vout may be in 10-16V range probably. 

You now know wiper pin.
Either of end pins can go to either of the remaining two positions.
Swapping them reverse rotation direction for increasing voltage.

If this is now not working there is something else wrong with your circuit.



Added:

Take a BARE LM317.
Put a cap at Vin and Vout (anything - 1 uF, 100 uF,...)
Ground ref terminal.
Put 220R from Vout to ref (this is essential).
Apply 18V to Vin.
Measure Vout.
If it is not ~~~= 1.2 V rejig brain and try again.