This simple circuit will let you check if a crystal oscillator is working. Simply connect the crystal between the two labelled points, and connect 5V+ to the power connector. If the LED lights, then it shows the crystal is functioning correctly.





All of the components should be readily available, and the transistors can be changed to most compatible NPN transistors.

You can also view the crystal waveform on an oscilloscope by connecting a probe to either the base or emitter of transistor Q1.

The Eagle files for this project can be found here.