I will check your way...I was going by pin 19 being green and buzzing to earth and on top side of pin (plastic) is labelled 19 (being far left) ...with otherside being 1... 
Sorry Marty, please re-read my post above... very right is pin 1
OK...I'm getting tired so I will pull the pin shortly...I apologise if I'm not doing this correctly...
I've run gnd off the COM on the PSU. On pin 12 (DC) I'm getting 4.9v. On pin 04 (DC) I'm getting 0.0v. On pin 3 (AC) I'm getting 0.0v. On pin 13 (AC) I'm getting 0.0v.
No need to apologise Marty.
Measure between Pins 3 and 13 for the AC voltage i.e meter on AC volts put one lead on pin 3 and the other on pin 13, should have a reading of 5 VAC
OK, DMM between pins 3 and 13 on AC. 0.0v
Ok, if thats correct then thats a problem. You need this for the displays
