Power Supply Ticking, Light Flashing My Arduino came with a 9V 1A power supply to use with it.  I decided to test it out with my multimeter.  I put the red lead in the connector and the black on the outside.  Sure enough I read 9V.  However when I tested the amps this did not work.  The meter read a low value and the power supply started making a ticking noise and a light started flashing on it.

I did have the multimeter on the correct settings.  Looking online I now realize that you cannot test the amps this way and as I was essentially testing a circuit with no load on it.

What I would like to know is what the power supply was doing when it was ticking and flashing.  It is alive and well so I suppose it was some sort of internal protection.
It was "hiccuping" in order to prevent damage from the short circuit condition. Once the short circuit condition is removed, the PSU restores normal operation.

From the reference:
"The operation of hiccup is as follows. When the current-sense circuit sees an over-current event, the controller shuts off the power supply for a given time and then tries to start up the power supply again. If the over-load condition has been removed, the power supply will start up and operate normally; otherwise, the controller will see another over-current event and shut off the power supply again, repeating the previous cycle."