I know it's been mentioned but be very careful taking measurements in and around the power supply and scope. If you can use some grabbers with your volt meter, that would be the best. Shut the power off, make the connections carefully (the caps hold a charge) and then turn it back on and read the voltage.
If you don't have grabbers put tape around all of the exposed metal on the volt meter lead except the tip. This will prevent accidental contact with something you don't want to touch.
Be careful! The 18 can bite..