John or RTR- I finished assembling my board recently. I'm having a bit of trouble getting +5V out of U1. Appears I may have a short from U1 pin 3 to 2 somewhere. I did verify no solder betweeen the leads of U1 as pointed out they are close. I'll double check that and some other stuff.
My question is when powering up for calibration using the 'Stan procedure' should the power supply to the signal tester board be current limited if using only an external 18V AC power supply? or (and) is TIU necessary for calibration?