From the picture it looks like you're using 100R for the resistor ... depending on the led type, this could mean 30+ mA draw, which exceeds the ratings of many LEDs ... try resistors in the range of 220R to 1K.
From the picture it looks like you're using 100R for the resistor ... depending on the led type, this could mean 30+ mA draw, which exceeds the ratings of many LEDs ... try resistors in the range of 220R to 1K.