I had to move a previously installed and working track about 18inches from it's original position. I tested it in it's new position and it worked. I screwed it to the ceiling and it didn't work. Took it apart, put it back together. Nothing. There is power to the feed connector but none of the lights will work. There is a 4' strip, an L connector and an 8' strip. Could the 4' strip (which the feed connector plugs in to) need to be replaced?

If you remove end cap of track, may be able to measure voltage. Recheck connections to first track.

Do a simple test: Secure the power, then install an incandescent light fixture--turn on the power, and see if the light fixture works. If it works, then you have a problem with your track. If it is the track, do not run it back to the store, first re-install to ceiling--making sure your track lights and connectors are installed properly--then turn switch on. If it still doesn't work, then your track lights may be off the tracks, so try playing them back in the correct position. If this doesn't work. The get a refund! ;)