I have just started experimenting with electronics and am concerned that I may have destroyed my LM339 comparator circuit. As a basic test, I had a 3.0 volt power supply hooked up to the Vcc pin and one of the + input pins. Nothing was hooked up to the corresponding - input pin. The long leg of the LED was attached to the corresponding output pin with a 1kohm resistor in between. The short leg of the LED was attached to ground but the comparator GND pin was not. I expected the LED to light up when I flipped the power switch.
When I flipped the power switch, The LED flashed briefly and then went off. After this incident, I verified that the LED was still working. Now I am trying to figure out if the comparator is broken. How can I do this using my multimeter? What are some basic tests I can do to figure out if the comparator is working properly?