U3 voltages

[tazman]

What am I measuring between? Pin 8 and? Pin 4 and? Also, looking a the schematics I still am not sure as to the pin numbers. Could someone help me please?

Thanks

Rob

[tpryan]

Unless the directions say otherwise, voltages are measured with respect to PGND. You can find PGND at pin 2 of the power connector, as well as many other places around the circuit.