Use a multimeter. Most will have a diode setting that will push a small amount of current thought the led, and light it just enough to see the colour.
Raven beat me too it.^
Type: Posts; User: lWither
Use a multimeter. Most will have a diode setting that will push a small amount of current thought the led, and light it just enough to see the colour.
Raven beat me too it.^