I have a 5V and a 12V power supply. Both have a N, L, Ground
connections for the AC side. Both also have a V- and V+ connection.
Measuring between V- and V+ I get the correct voltages, i.e. 5V and
12V. Measuring between ground (AC side) and V- on both the 5V and 12V
gives 0V.


** Use a * ohm * meter to check for continuity.

Bet the 5 volt one has no connection from AC ground to the DC output.

Most simple PSUs have the DC output "floating" ie not connected to safety
ground.




......... Phil