My track light was working fine, it has been up and lightin fir 3 years. Suddenly, 1 light went out. We had the bulb tested, along with the track head, they are fine. Over a period of 1 week, 2 other lights are no longer working. We have bought new heads and bulbs, tried re-positioning them along the track. Nothing works

It is hard to believe there is something wring with the track itself. As the electrician said, it is just wires.