Modem Symptoms

I have an external modem, and the lights do not come on when I use it.

First Step : If the modem is powered, check that it is receiving the proper power signal, and it is switched on.
More information : Some external modems require a mains power cable. If this is the case, check that the mains socket is supplying power, and then check that the cable is working. If you have a known-good cable try using it. If you have the proper equipment, it may even be worth testing the power to see that the correct voltage is being supplied.